USB - How much power can it deliver? (regarding cellphone charging)

[cirrus1]

I'm curious about how much power a USB port can deliver. I'm about to buy a charger for my Ericsson T28s that plugs into the USB port of my laptop. I'm just wondering if the charger is able to recharge as fast as the normal AC charger. The AC charger is rated at 5V 0,65A output.
AFAIK there are several speakers that plugs into an USB port and nothing else. They most likely consume more power than my cellphone ever will .

Although I am pretty sure that the USB port can deliver enough, I'd like to now the correct specs

Thanks

 

[cirrus1]

^up goes

 

[crypticlogin]

The USB Consortium's homepage

A *really* quick skim of the USB1.1 specs keep hinting at a 0.5A maximum directly from the USB port with a 4.75V (bare minimum) rating. The docs for USB1.1 (and USB2.0, if that interests you) are under the developer's section, under "download". Hope that helps.