i just found this old articlehttp://www.cyberciti.biz/tips/linux-swap-space.html
"Here is my rule for normal server (Web / Mail etc):
Swap space == Equal RAM size (if RAM < 2GB)
Swap space == 2GB size (if RAM > 2GB)"
"My friend who is a true Oracle GURU recommends something as follows for heavy duty Oracle server with fast storage such as RAID 10:
Swap space == Equal RAM size (if RAM < 8GB)
Swap space == 0.50 times the size of RAM (if RAM > 8GB)"
the comments are interesting, if you can read them, they are informative too
i personally have 1 gb of ram but i only have seen maybe 300mbs of the swap used from 3 gbs available(i created it that big) so it was a waste of hard disk space
it also mentions that you should have double of ram in laptops for hibernate, something i have heard in the past but never used so can't confirm
i remember that someone on this forum said that you can have a system without a swap partition but never tried to do it, with 1 gb of ram you always feel that you are going to need swap