If you need a style that works for Google Search, Reader, and AdSense Reports, please give Google: no ads and compact a try.
I recommend users to install Gmail *2* small attachment icons, too. It makes Gmail's attachment icons look prettier.
The icons in left sidebar is from Gmail *Mobile me* [obsolete], thanks to Nic\o/@userstyles.

Attention:
1. It works only for Gmail 2.0, but not for other Google services.
2. It works best with Gmail "Tree" theme.
3. It doesn't work with Gmail Labs "Right-side chat" and "Right-side labels" features.
4. The "Invite a friend" area must be placed at the *last* position of the sidebar, so that it can be removed.

For more detail, please visit my gallery
http://picasaweb.google.com/chiahsien/StylishForGmail20

ChangeLog:
2009-08-31,
Update for Gmail recently update.

2009-06-06,
Fix: Gmail changed its HTML codes, so I changed mine.

2009-04-20,
Fix: Icons incorrectly displayed in "Chat" window.
Add: Hover effect in Settings.

2009-04-14,
Fix: mail can't display when ope