I wonder what you guys do with the beer you have left over after racking to you kegs. I was thinking of bottling mine but am having trouble trying to come up with a solution to carbonating the bottles if I don't really know the final volume.
How much are you talkiing about? I suppose you could rack into old soda or water bottles and pressurize with a carbonator cap. If I have a pint or two left, I usually just rack into a pint glass and drink. If I had a couple gallons left, I suppose I'd throw it in my 3 gallon corny.
I was in a similar situation recently. I was kegging for the first time but the kit I was using up here in Canada was 23 liters (5 english gallons or 6 US gallons) so I knew there was going to be some leftovers when I racked to the keg.
The simplest solution would be to get the carb tabs. However, when I went to the LHBS to ask about them the lady said that she had bottle bombs the last time she used them so didn't carry them anymore. I didn't ask her how long ago this was.
In the end I estimated how much I would have left based on a previous batch and measured out the appropriate priming sugar and bottled the remaining as if I was bottling the entire batch. Was really a PITA to sanitize and clean up my bottling equipment when I was kegging so will be looking a lot harder for carb tabs before the next batch is ready to keg. Then when I move up to extract I will be making 5 US gallon batches so they fit in the keg and I won't have this issue.
+1 on the carb tabs or Coopers carb drops and a couple of swing tops. The thought that I had to bottle 50+ bottles of beer would make me quit brewing, but sanitizing a 2 or 3 swing tops is quick and easy and makes for good travel beer.