ooh, I only see we have a fishies section to this forum too... I love me some fishies... have taken a 2 year break for the first time since I was a kiddy. But allready started up the first small pond a week ago... the big one is going to require some work to fix up again and I'm still adjusting to the less moderate climate...
Anyhow, if your tank is about 100l you can keep the betta with other fish, just not more male bettas... I used to keep a male and some females as well as some dwarf gouramis... (which are actualy closely related - enough for them to give each other the evil eye, but not enough to lead to more than the basic "who is in charge here" scuffle. Dwarf gouramis are some of the easiest fishes I ever bred... unfortunately very messy nesters if you are trying to do planted aquariums. :P Oh and the babies are minute its like shaking pepper on the water... at least they are good parents for the first few days (the males). Breeding is similar for other bettas.