The BBC News website takes a second look at some of the mobile games now available. You skip straight to the different reviews by clicking on the links below.
Call of Duty (Mforma)
A shrunken version of the title that has been a huge favourite ever since it appeared on the PC.
The phone version does not look this good
One of the most compelling parts of the full version of Call of Duty on PC was seeing your fellow GIs and comrades fight and die alongside you. The detailed graphics helped establish a great sense of atmosphere too.
Replicated from the full version are the different battlefields that include the D-Day landings, the battle of Stalingrad and the fight for Berlin.
It's fair to say that the phone version struggles to re-create that experience. The limitations of the phone have led developer Mforma to turn it into a squad-based shooter that uses only three troopers rather than the many more in the full-size version.
This turns it into something that more resembles Commandos in that you have to pick a small squad from a team of specialists that includes sniper, infantryman, media, commanding officer and engineer.
Each of them has slightly different abilities and some of the missions are tricky unless you get the mix of skills right.
As a result it's more tactical than the full version and demands a player make good use of grenades and other special abilities to get through the levels.
One character in the trio you control is usually in charge and can tell the others to take cover if the opposing fire is getting too heavy.
The problem is that the canvas used by the original Call of Duty is so broad that this version suffers by comparison.
It can be hard to tell which of your squad members you are controlling and if you spend too long working it out the Germans will shoot you down.
The sounds are pretty monotonous too and the enemies show little of the ingenuity and intelligence you might expect if you are fan of the full-size version.
Splinter Cell - Pandora Tomorrow (Gameloft)
A port of another popular title on consoles and PCs featuring the sneaky exploits of special agent extraordinaire - Sam Fisher.
Sam Fisher can now sneak about on your phone
Like all the other outings for Mr Fisher this one combines lots of shooting with lots of creeping around. This one is about eliminating Suhadi Sadono who heads an Indonesian guerrilla group.
While it does not have the sprawling feel of the full versions this pint-sized outing for Sam Fisher is pretty good.
The game does a good job of exploiting the fact that Mr Fisher spends most of his time sneaking around in the dark which means the game can get away with minimal detail in some scenes.
It is an effective touch and adds a good deal of atmosphere.
The different screens in the game make great use of the restrictions on the phone which, as you might expect, make the business of sneaking about a good deal tenser.
You will need to make good use of Mr Fisher's abilities to finish the game and doubtless struggle at times to keep the alarm meter from hitting the danger zone.
It's not just a sneak-fest either. Sometimes it will take a while to work out how to get through a level.
If you are playing it while you commute, keep an eye out you could easily miss your stop.
Lord of the Rings (Jamdat/In-Fusio)
The mobile game of the third film in the series that puts the player in the boots and shoes of some of characters from the movie.
Keep the story alive on your mobile phone
It is a side-scrolling slash-fest that involves hacking down lots of enemies with swords in traditional fantasy style.
Characters can be moved around with joystick or keypad and you might find yourself making more use of the keys because many of the characters have special abilities that are best called up with a tap on a key.
This does mean that the game takes a while to master and in its early stages, when you are getting used to controls, it can be a bit fiddly.
It also suffers the usual problems of side-scrollers in that you have to be facing the right way to hack at the foes and when you are facing lots of them this switching back and forth can be a bit dizzying.
You will also have to learn neat key combinations to avoid the missiles of some enemies to get close enough to attack.
The levels are well laid out and you have the usual ladders to scale, obstacles to avoid and leap over and barrels to smash to find healing or hiding potions.
There are checkpoints scattered about that mean that if you die, which tends to happen a lot, then you do not have to back to the start.
Graphics are good enough but the small screen can mean that details are a bit lost. The orcs look a bit hairy and some of the other characters are a bit indistinct too.
You can upload best times and scores for the levels to see how you compare with other players.
Pocket Kingdom (N-Gage/Sega)
We have not played this game but it deserves a mention for its bravery.
Adventure, travel, doom and glory - a day in the Pocket Kingdom
As its name implies Pocket Kingdom is the first massively multi-player online role-playing game for Nokia's N-Gage game phone.
Before now such games have only lived on PCs and consoles that have quite a bit of processing power to play with and a fast net connection.
It's a measure of how far things have come that this can now be done on a phone, albeit the Nokia N-Gage which is, as handsets go, among the most powerful and happens to be a dedicated gaming gadget.
The game is set in the World of Ulgress and, like similar titles, gives you the job of adventuring through the world building up skills and cash and researching and creating new magical items.
You also have to build up an army to grab more territory and turn your kingdom into an empire and there are many different unit types you can recruit to do the job.
One of the factors that makes these online MMRPGs popular is the community that springs up around them. And Pocket Kingdom is no exception.
Via the website you can see real-time leader boards, player auctions of characters and kit, chat rooms and more.
You will need an account with the N-Gage Arena that co-ordinates play. You can sign up for this via the web.
Once you've downloaded it you will need a GPRS account with your mobile phone operator to play the game. As you are interacting with a persistent online world you need to be there to play properly.
Depending on how you pay for your GPRS account this could end up being a bit pricey as some mobile phone operators put a fairly low cap on download limits.