I have Ubuntu 12.10 installed on a 16gig flash drive without a swap partition. I heard from many users that skipping swap on installing Ubuntu on flash drives extends the speed and life of a flash drive significantly (Kingston CS says they've yet received flash drives "worn out" from installed OS use).
My flash installation runs very well, though sometimes there is some sluggishness with Firefox working with image laden sites, or with Gimp, but I don't know whether to fault that specifically to swap.
On the whole there are no crippling performance issues. My question is would there be any real performance improvements had I installed swap (since I might format another Ubuntu flash drive)?