Yeah I put the swapfile on my SSD - otherwise there would be no point to having it really... unless you have one of the older models with really poor random writes (<80MB/sec). Although BSA is correct about TRIM eventually leading to slower performance, if you read through the specs - you're talking about a looong time before that happens.
Even in the absolute worst-case scenarios (i.e. running the drive with nothing but random writes ocurring 24/7 and a very small MLC drive - you're still going to get at least 6-months to a year out of the drive)... when you take into account a larger drive, SLC or better managed MLC (over allocation, controller managment algos, etc) and the simple fact that your PC is never going to be in a 5K IOPS demand state - no matter what you're doing with it and it becomes a non-issue. Do the math based on the specs of your drive divided by 10, andd you'll come up with somewhere in the area of 5-25 years for most SSDs under pretty heavy use. (Since drive manufacturers like selling snake oil as much as cable manufacturers - I would reduce everything in their stats by 10X - so if they say 5M cycles... at best consider that 500K cycles, if not 100K cycles).
In any case, think about what hard drive you were using even 3 years ago - if it's the same one you're using now... then by all means put the swapfile somewhere else... especially because you're using a 3 year old SSD which is much worse than they are now!
However, even if that is the case, I would warrant that you don't use your PC 24X7 as a server - therefore much of the time it is simply sitting idle and doing nothing - thus not wearing anything down at all. In most common analysis cases the average user spends 8-10 hours per day on their system generating at the very most 75GB worth of total writes... which even on a 16GB drive will still get you through a couple years even by a conservative 10K-cycle lifespan not to mention the 500K to 5M specified by current manufacturers.
That being said - although I run my swapfile on the SSD - I never, ever set it to more than 512MB - and often just 64MB. After all, I'm running 16GB of RAM - so the only thing that will even be trying to use the swapfile will be legacy applications - which shouldn't be expecting me to have more than 512MB of RAM anyway... if they even run in a 64bit OS - which I doubt.
Add to that the fact that I change systems and hard drives only slightly less frequently than I change my socks (OK - kidding, but seriously at least twice a year I either add a HD to one of my systems or replace one with a newer/faster/larger model).
YMMV tho.
Food for thought if you're interested in further reading.
