Comcasts's "Powerboost" service was launched last June, and our users have reported they've seeing on average about double their normal speeds during the first few minutes of a download. One user claims to have reached 64,000kbps downstream. Of course these speed increases only apply to traditional downloads in bursts, not peer to peer traffic, and it doesn't address our users' biggest gripe: paltry upstream speeds.

Comcast uses a homegrown patent-pending technology for Powerboost, but the idea of speed-on-demand is catching on with other providers. The PacketCable Multimedia (PCMM) specification technology fueling a speed preview service being tested by Cox, is from Camiant. Camiant's CEO recently praised such bandwidth on demand solutions:

"This obviously leads to satisfied customers who enjoy a speedy transaction, but it also leads to happier, better-performing networks. It's a well-known phenomenon that the gains of statistical multiplexing are maximized when the duration of sessions are short and bursty, as opposed to long and sustained. A short session at a higher throughput is better both for subscribers and for networks than a sustained session at a lower throughput."

Whether the service is a PR stop gap measure to appease users until the next upgrade or an essential broadband perk is a continuing point of contention among users in our Comcast forum. Former Comcast users who have been transitioned to Time Warner Cable as part of the Adelphia deal find they miss the extra speed. General forum consensus? The technology is "pretty awesome."