Every time I need to create a menu or toolbar with actions I end up collecting some images extracted from different application and hand tuning them with the image editor. This
A good website to track is Smashing Magazine I keep the RSS feed on my iGoogle page as the regularly have articles along the lines of 50 Beautiful Free Icon Sets For Your Next Design. They're a bit "graphic designery" if you get my drift but they do provide some really useful stuff.
I guess it is almost impossible to get "copyright-free" glyphs. Even Open Source is not copyright-free!
But if more-or-less-free-for-use glyphs are ok, then you might give glyFX's free icons a try.
There are the silk icons (and others from famfamfam). Those are not copyright-free, but I figure you meant they needed to be unencumbered, free-to-use, etc. (Truly copyright-free stuff will be very, very hard to find.) The silk ones just require acknowledgement somewhere, nothing else.
We use IconExperience which is royalty free. You buy a licence for a company. They do two different libraries, one called V-Collections and the other X-Collections. There are various sections within them, that you can buy separately, but for V-Collections its $379 at most and X-Collections its $289.
Try the Fugue and Diagona icon sets. Again, they're not copyright-free, but can be used in exchange for attribution.
Gnome has good icon sets and the licence is GPL. http://art.gnome.org/themes/icon