If Vista continues the "tradition" you cannot stop Windows from paging, even if you delete the page file. I have not tested Vista yet so I cannot say for sure but I would wager that MS did not budge on this.
An old XP trick is to make your minimum and maximum size of your page file the same size. This way, your system does waste time repeatedly resizing the page file size based on the ever changing amount of available memory. Again, I have not tested this on Vista.
If you are feeling adventurous, you can try it and see how it does. The old rule of thumb was to make the page file min/max at 1.5x to 2x the size of your memory. With 3gb, I'd suggest the page file be 1x to 1.5x the memory amount, aka 3072mb to 4608mb. Also, putting the paging file on a physically seperate HD from the OS is usually a good tweak to relieve system disk I/O loads.