This may be a common sense hint, but it was a "dawn breaks over marblehead" moment for me, and it might help others. When doing research on the web I typically drop any relevant URLs into a folder of bookmarks in Safari.
Recently I wanted to send a group of about 20 URLs to a colleague. I know that you can drag URLs from the address bar to the desktop (or other apps). However, I just figured out that you can open the Bookmarks page (Bookmarks -> Show all Bookmarks or click the bookmark icon in the toolbar) and highlight the URLs there. Then copy and paste (or drag and drop) into applications such as Mail, TextEdit, etc. as well. What's nice about this is method that it just drops the URL (in plain text, no less) and no other information.
[robg adds: Safari will highlight everything when you select it, but very nicely ignores everything except the URL when you actually copy the selection. Quite nice...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=2004052511501794