I found this excellent tip in Ovid’s LiveJournal.
And if you use Firefox, here’s a tip that many don’t seem to know about: keywords.
Let’s say that you’re constantly searching images.google.com. Go there and type a search for “daisies” and bookmark the resulting page. Then, goto “Bookmarks -> Manage Bookmarks” and select the bookmark you just saved. Ricght-click the bookmark and select “Properties” (or “Edit -> Properties” from the Manage Bookmarks menu). In the resulting dialog box, you can edit “Name”, “Location”, “Keyword” and “Description.” The “Location” will look something like this:
In that URL, find the word you searched for (“daisies”, in this case) and replace it with “%s” (without the quotes):
Then, type “images” (without the quotes) in the keyword field. Click “OK”.
When you’re back at the browser, you can now just type “images” followed by what you want to search for and you’ll go straight to the google images page for that. Try it with “images puppies”, for example. This technique will work for just about any site where you can search.