Parallel charging

as long as you are doing a balance charge and the packs arnt way off in amount of remaining charge you will be fine.

I take your point Duck that with a good balance charger, it wouldn't matter so much having them in series because it can balance all the cells independently anyway, but that's with a good balance charger. I know that my charger can take AGES to balance cells. It does a good job, but once the charging current cuts down as the pack gets full the balancing process can take up to, or even over a hour.

Another benefit to series charging is that a charger such as mine has a max output current of 5a, whether that be at 11v or 22v, so series charging basically allows you to double your output current

I've just put a bid in for one of these:
cgi.ebay.com.au/RC-lipo-battery-balance-charger-plug-3s1p-3s-11-1v-x10_W0QQitemZ200387451215QQcmdZViewItemQQptZAU_Toys_Hobbies_Radio_Controlled_Vehicles?hash=item2ea805d94f&_trksid=p3286.c0.m14

I figure i may as well make up a good balance board that can charge as many batteries at once as I'll ever want to, with a deans connector going to the tabs (in series of course) so that it can just charge through the balance tabs - that will save me having to make up a deans parallel cable for 3 or more batteries. My charger's max charge rate is 5amps, so if I have at least 3 packs hooked up that will be 1.7 amps each, the balance connectors will handle that much current easily.

The one I want to make will basically be the same as this:
www.rcgroups.com/forums/attachment.php?attachmentid=2699126

Very nice. Only thing to be of concern is that all current is traversing that board. When packs of different potential are connected, potentially massive currents can flow between the packs as they balance each other. This is because of the very low resistance of the packs. When I parallel charge I also parallel the main leads, and connect this first and leave for a few minutes to allow the packs to settle together. The maximum difference between cells in divergent packs is suggested as 0.3V in the RCG thread created by Jules. Others say upto 0.5V is still safe. I tend to get them as close as possible prior to connecting together.
I would suspect with your board and setup where only the balance leads are connected you should be very careful about this factor. The balance leads are capable of carrying a few amps, if you have quite a difference between cells potential, the current at connection time could be much greater.