If you don't like watching the Finder's "snap to grid" animation, open Terminal and enter this command:
Defaults write com.apple.Finder AnimateSnapToGrid -bool FALSE
You'll then need to restart the Finder (using Activity Monitor, Terminal, AppleScript, logging out, or whatever other method you prefer) to have the change take effect.
Mac OS X Hints
http://hints.macworld.com/article.php?story=2007051903403932