Omline sims, kinda, but with sooooooooo much more potential. RPG stuff mixed in as well. Basically, anything goes. People are writing code to enable them to do all kinds of things - drive boats, play football, scuba dive, endless potential really. It seems that the users, are really embracing the potential.
The initial set up is free. You can take part in the "environment", chat, explore, interact all for free. I'm still pretty new to it so I'm unsure of all the details, but I can assure you that I've spent 4 or 5 hours "in-world" and not spent a penny. I've not been asked for any sort of payment details whatsoever. It appears, that on the "surface" there are no costs. I think the only cost comes when you want to "purchase" stuff, ie: Land. I should point out though, that although I haven't actually spent any "real" money, I'm finding ways of making/finding "virtual" money all the time.
The environment, is developed by the users. The features and the cost of those features are all defined by the users. Therefore, just as in the real world, you can buy software (M$ Office) and get shareware alternatives (Open Office) for free. In this virtual world people are making stuff you pay to use and other people are making stuff that's free to use. (well that's the way it seems to me anyway)
As I said, I'm fairly new to the whole thing, but seeing as this forum is a "virtual" environment, I thought there may be some interest for a more dynamic, experience.
Well, enjoy what second life has to offer, but as my wife said "don't forget your first life"
J