Broadband users in Britain will be able to temporarily boost their speed under plans put forward by BT.
BT wants to tempt more people to tap into broadband
It is to try out a "flexible broadband" scheme which would allow surfing speeds to quadruple at the click of a mouse.
The trial is part of four broadband schemes announced by BT, which it hopes will help it reach its target of five million high speed connections by 2006.
The telecoms giant is facing strong competition from other internet providers such as Tiscali and Telewest.
With BT's flexible bandwidth service, customers will be able to increase the speed of their connection from 512Kbps to 2Mbps whenever they need a faster downloading speed.
Though the price is yet to be finalised, it is expected to cost one to two pounds per gigabyte downloaded.
The trials are due to start next month and the service due to be officially launched in the autumn.
BT is also strengthening its ties with Yahoo, with a new product that will allow people to make phone calls over Yahoo's instant messenger software.
Called Yahoo Messenger with BT Communicator, it is to be launched later this year using the voice over internet protocol technology.
It is designed to make it easy for people to switch from exchanging instant messages to a telephone conversion. Calls will be charged at normal rates and appear on the phone bill.
Among BT's other plans are a new service deal using intelligent net routers in a customer's home and a "rich media" digital rights scheme to manage and distribute content.
BT has signed a deal to show episodes of ITV drama The Bill on a pay-per-view basis and is also promising more DVD-like quality content.
"These new products and services provide broadband that is flexible and powerful enough to meet the customer's every need," said Pierre Danon, chief executive of BT Retail.
"They demonstrate clearly that there is far more to broadband than speed, as there has to be if we are to realise mass adoption far beyond the current two million mark."
BT dominates the broadband retail market in the UK. But its rivals are snapping at its heels, competing on both price and range of services.
"Broadband is key to BT," said Michael Philpott, an analyst with the telecoms research firm Ovum.
"They will have to be successful on the wholesale and retail level if the company is going to succeed in the future. But they are in a worrying state at the moment."