Windows always recommends 1.5x your RAM for swap for some reason, though in practice, with 1 GB, you're likely to never touch the swap file, so unless you're doing RAM eating tasks, you could get away without a swap file. I have one anyway though just in case, because I've got the disk space to waste, and having it means it won't fragment in the case it does suddenly get used. I rarely go over 700 MB of virtual memory in use - of which 150 MB tends to be Mozilla as that seems to eat more and more memory as time passes, forcing me to restart it once every week or two, which is annoying