If you have a spare USB memory stick (a 2 GB one is quite cheap anyway these days) you can plug this in and use "ReadyBoost" to improve the performance of the swap file. This can help a little with speed issues.
To do this, simply right click on the "removeable disk" and select Properties. ReadyBoost will be one of the tabs available.
Normally USB stick memory is not as fast as a hdd swap file, but Vista uses it intelligently to ease some of the pressure off. So this doesn't work as well in XP and lower, although there are ways of implementing it.
Hopefully, the upcoming USB3 standard (which is reported to be 10 times faster than USB2) will improve speed even more, but it will require a hardware change, and is only available on expensive high-end motherboards at the moment.
Of course this doesn't alleviate the need for good housekeeping - and an 80GB hdd is very small by todays standards.