My laptop isn't really high-spec, and I use mobile internet, so I can't really download and play Second Life, much as I would like to. But I did create an account in IMVU, and got completely caught up in the whole shopping thing. It was so much fun. Once I found I was able to buy credits through my mobile phone, heck I would spend hours browsing the outfits and hair styles.
I came out to the second person ever through that, and it was the most surreal experience you can imagine. We were sat around a table, in a Japanese style house, with strains of Koto music playing in the background, and a view of the ocean, drinking tea and just generally chewn' the fat.
She wanted to know why I'd chosen a female avatar, since she knew me as male, and it just sort of all came out. Very strange, baring your soul to an albino cat woman with a huge samurai sword strapped to her back, lol. But I felt so much better afterwards. And she gave me a black rose.

Unfortunately, she has since disappeared from the face of the net and, since no one else I know uses IMVU, or knows me for me, I've stopped using it. Right after I bought a huge, gothic castle to lounge around in, lol. It does have AIM or MSN beat hands down though... there's nothing quite like chatting on the back of a giant eagle, soaring through the sky above the clouds, bathed in moonlight.