I use MemWatcher from
http://matrixsoftware.com
Try to find a version 3.xx as this does not time out without registration, the laters version 4.xx seems to, there is no known hack on any of the usual sites, but the program is cheap, version 3.xx has a nag screen at start & End only.
If you cannot find version 3 (MW30.exe) I have a copy here but its probably to large to attach IF I knew how.
If you can use FTP let me know in a PM I'll give you guest access
so you can get the file.
Snark.