d_golem - there are pygmy cories but Im not sure Id trust them with bettas. They are neon tetra sized and don't quite behave like normal cories. Panda cories tend to stay smaller than some of the other ones. Rarely go over 2" if I remember correctly. You could probably get away with 3 panda cories in your tank if you make sure to not add anything else and keep up with your waterchanges when they grow.
magickzzl - Eeek! it sounds as if mine are being nice and well behaved now in comparison o_O Hopefully it'll go well with your bettas.
maries - bettas are facinating to watch. I had no idea it'd be this fun. I mean I've had bettas before but seeing them interacting with one another in a larger tank is great.
glitterfish - thank you

PitchBlackMoore - they flare lots and one of mine (the alpha betta, illyria) has built a good sized bubblenest. I'll post a photo of it.
TamtheLittleBlackMoor - It wouldn't surprise me if 3 out of the 5 I have were wild crosses. They are a mixed red and blue colour (like you can see) with a fairly dark body. I think it looks like the wild colour that's been mentioned. One of them is a darker blue with almost no red and the last one is pale, almost white with red and blue fins. Plakat bettas are gorgeous I find.
I mean so many people want only the huge finned ones (which I do understand) but even comparing short finned females to alot of other fish out there, they are gorgeous! so I don't see why they can be so hard to get at fish stores and alot of people don't seem to like them.
coyote ugly - Im sure you'll find pretty girls (I haven't seen an ugly betta yet)
Good luck with setting up your 15 gallon tank.
tinkerbell - thank you

Here's illyria with her bubblenest:

and flaring at Snow white:

Snow white and Illyria are the only ones Ive named so far. The three who look wild coloured haven't told me their names yet.