Simply head to http://www.geocities.com/queerasjohn/lj.html (since LJ doesn't allow linking to javascript) and drag the LJump! link to your bookmark bar and when you click it and enter a username, it will take you straight to their journal.
Similarly, LJoo? is the quickest way to get to someone's userinfo page and works in much the same way. Again, head to http://www.geocities.com/queerasjohn/lj.html and drag LJoo? to your bookmark bar. Thanks to
Will this change your life? No. But will it make your LJ experience that much more thrilling and meaningful? Also no, probably. But it's kinda nifty, and apparently

PS. If you happen to know how to make LJ display the links, let me know.
PPS. LJump! and LJoo? are subject to the Creative Commons license. Basically, spread it around but don't say it's yours. I'd prefer if you linked to this post rather than posting it in your own journal, but whatever floats your boat.