Absolutely. That's what these boxes are for.
I had a lot of trouble looking through Sony's site for data on the PS2's network adapter, so I couldn't get specifics about what sort of speeds it runs at, etc. On the other hand, Microsoft's XBox site is crammed with details about networking the green machine.
Since I've seen many networking products advertised as being for
either the XBox or PS2, I'm assuming that they are fairly well equivalent in their networking requirements.
Take a look at
Linksys' WET11 Pages for information about using the WET11 with a PS2. Linksys also makes an 802.11g wireless bridge called the WET54G-
here's more information on it. They even have a product called the
WGA11B that is aimed exclusively at connecting game consoles wirelessly.
I couldn't find as much info on D-Link's or SMC's sites, but they also make products like these, and you can find help with setting up their products for game consoles on their support forums.