I tried the new Google Code Search and it looks promising including support for regular expressions. But it seems to not find things as I wish it would find.
Does the code really need to be in an archive like zip?
Take a look at this search for some code I have in an AutoLISP file:
It finds one in a newsgroup that is zipped. Why could it not find this file I wonder that is not zipped:
Another wish is that it could find code snippets on web sites and blogs.