I have the same issue.
Windows 7 x64. VS2008. Every time it does a syntax check or anything like that it adds up another 10-20mbs to memory consumption.
I have to restart it a couple of times every afternoon because I run out of RAM.
I have IIS and an SQL2005 running, but nothing other than that. No addons or anything except for Tortoise SVM.
Any suggestions, anyone?
EDIT:
Actually it turned out I was coding in an aspx file with some custom tags, so everytime i would modify it, intelliscense would signal some errors. My guess is that it keeps a history of these errors, and manages the memory very-very poorly. So, it found 7 errors and that ate up 15-25mb every time.
The only way I could get around it was to code in included files.