I use Subclipse as a plugin for Eclipse / Aptana, and there is no hotkey to perform a commit. This means anytime you want to commit something you have to navigate the file tree and then the context menus to commit, I'd rather not leave the keyboard to do a commit.
So after some digging around I figured out how to add a hotkey, and I wanted to share.
Open Eclipse / Aptana
Window > Preferences
In the filter box, type "keys"
Scroll to "Save All" and double click it.
In the Command field set change the Category to "SVN"
Change the Name to "&Commit..."
Change the key sequence to the key combo you want to perform a commit. I use alt + shift + s, but that might be weird for some folks.
Click Add
If you were successful you should be able to use your key combo to perform a commit for now on.