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[img src="" caption="" credit="" alt=""]AOL is widgetizing AIM with the new Wimzi widget: like other chat widgets, this lets you chat with your website visitors in real time. It comes in both Flash and javascript versions, so it can work on MySpace, Piczo, hi5 and elsewhere. When you're signed in, it displays your buddy list, meaning you wouldn't need to run AIM on your desktop.
AOL also announced the integration of AIM into their webmail offering: a similar idea to GChat within Gmail. Once again, this gives you more options than just downloading the IM client.
Rivals include Meebo's MeeboMe, which supports multiple IM networks (not just AIM). For a summary of the IM space, see Look Out Kevin Rose! 19 IM Startups You Need to Beat.