I used to be a pen and paper role player. I started with MERP (Middle Earth Role Playing) system, then went to Role Master and finally AD&D. I liked RM the most. But that was ages ago. My old crew is all around the world now.
I also played a few on-line campaigns on a few different forums. Some were AD&D, some D&D 3.5 ed, some were just free style. Basicly, GM (or DM) presents a story and particular situation and then you post your reaction. Some GMs just decide what would happen, while some actually role dice (or say that they do
). It's fun, but not as much as pen and paper, especially since it tends to drag for ages. We never finished a single campaign. But there are forums that are actually dedicated to that kind of role playing and people there are more dedicated themselves, so campaigns run faster.