Greasemonkey comes to Chrome - get your userscripts ready!
Scripts can modify your favorite webpages in all kinds of useful ways, whether it's cheating at Mob Wars, adding nested replies to Twitter, or "unf**king Facebook." If you think a website needs a cosmetic alteration or a user experience facelift, you can probably make it happen with scripts.
Greasemonkey started out on Firefox, and has been added to Safari as Greasekit, but Chrome has a secret weapon. His name is Aaron Boodman, and he created Greasemonkey. He now works on the Chrome Extensions team at Google. Even though Greasemonkey on Chrome isn't yet as mature as the Firefox version -- 15-25% of scripts might not work on Chrome yet -- it will definitely get there with Boodman's help.
If you need some scripts to get you started, you can scope out Download Squad's 10 Greasemonkey Scripts You Shouldn't Browse Without, or peruse the large selection at userscripts.org.