Movable Life: Client-agnostic Second Life
Movable Life makes good on the obvious, that the client is just a window:
If you just want a quick and easy SecondLife experience without all the 3D graphics, then MovableLife is exactly what you are looking for.

Linden Labs’ support system is absolutely dismal. They don’t even provide a simple contact form or even an e-mail address through which you contact them to have your account e-mail address changed. Even MySpace—MySpace!—provided that level of support.
I guess I can’t check out Movable Life without registering another Second Life account…
How does this compare with ajaxlife.net?