I cut an inch and a half off of one of mine and used it as a brite tank. Gelatin in and then rack the beer into the keg. I usually do 2 weeks at room temp to condition and then cold crash 3-5 days. Then I push it in to a serving keg to carbonate. It makes for very clear beer and leaves lots of funky stuff in the brite tank (about 22oz total).
Well, that's how I did it for a year or so. But now I just ferment, keg and drink. Got the big pipeline established and I've discovered that if I just let the beer sit a little longer it clears itself. It sure is a lot less work.