Can a flash drive really be used as ram?

it depends on the speed of the stick but yes ,its called ready boost.
more here

ReadyBoost - Wikipedia, the free encyclopedia

It is kind of a retarded RAM. What it does is that Superfetch puts pages on the stick from where they can be retrieved faster than from a spinning disk (because sticks usually have a faster access time (e.g. 1ms) than spinning disks which are more in the 15ms range).

It really only has an effect if you have a small RAM (512MB or 1GB) and a fast stick. For any RAM 2GB or bigger it makes no sense because there is a certain overhead with Ready Boost that will work against you - it needs to write the pages to the stick and to the disk.

ReadyBoost - Wikipedia, the free encyclopedia

There's really no substitute for adding more RAM to a 64 bit machine, especially while it's so cheap. :)

Check the performance of your stick with HD Tune. Let it run till the end, else you do not get the access time. Post the result here. Then we can tell you whether it is worth it.