If, like me, you need to constantly go back and forth between a few spots in code, place (toggle) bookmarks by pressing CTRL+K CTRL+K, then you can go to the next or previous bookmark by pressing CTRL+K CTRL+N or CTRL+K CTRL+P. CTRL+K CTRL+L clears all fastmarks.
I overuse it during "Test Driven Developpement" to come back to my unit test !
I like having fast bookmarks like this plugin allows. But when I remap the keys in Eclipse preferences, the plug-in stops working. I'd prefer to have full key control, like "F2" for next bookmark and "Ctrl-F2" for toggle bookmark.