I want, no demand, easy access to my Dropbox.  This involves adding it to to the Favorite Links bar in Vista (just drag it there) and the Places bar.  On Windows 2000 and XP you can use Tweak UI, but it doesn't run well on Vista.  I can't recall if the Places bar customization didn't work on all versions of Vista, or just 64-bit Vista.  Either way the registy script is an easy way to make the changes.

Places Bar Before	Places Bar After

Registry Script to Customize the Places Bar

Copy and paste the following text into a new text document and save it with a .reg extension (eg. dropbox-places.reg). Double-click it to import it to the registry.

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\comdlg32\Placesbar]
"Place0"="Recent"
"Place1"="Desktop"
"Place2"="C:\Users\YOURUSERNAME\Documents\My Dropbox\"
"Place3"="MyDocuments"
"Place4"="MyComputer"

Make sure that you provide the full path to your Dropbox (usually this means you'll only have to replace YOURUSERNAME with your actual username.  The order will be Recent Items, Desktop, Dropbox, Documents and My Computer.  You can modify that, but don't create any more than 5 places (0-4).