headius: No. The normal is 6.5 in all these sizes if I had understand it right? At the current playing level of most of the people it is not problem, but of course more equal the better. I personally are not so sure which would be right komi.
Salkkuman: I would vote for 6.5 for all sizes. For those who think komi should be larger or smaller for 13x13 or 9x9, consider this:
Yes, there are typically fewer points in 9x9 or 13x13... ...but the first move is also that much more important.
I believe most sources agree these two factors balance out so that komi should be the same on small boards.
In actuality, I would prefer a configurable komi, so we could specify it at game start, but I don't know how that would work with the current rating system. Fancier go sites are able to make games rated all the time, regardless of settings tweaks, but BK is limited in that regard. Perhaps only rated for default settings (komi 6.5, no handi)?
headius: I think making komi a user-selectable value would be nice. Instead of getting handicap stones I could play a game with komi set to, for example, -83.5 :)