Getting rid of Gmail theme-backgrounds
I love that Gmail added theming functionality, but I would actually like some of the themes more without the backgrounds. This isn't a fancy solution, but it's more of a reference for myself. You could also use plugins that let you modify the CSS, but I'm just using Adblock-plus for Firefox here.
Take for instance the Pebbles theme:

Not my cup of tea, but I love those neutral colours.
The easiest thing to do is to add a Block-rule in Adblock-Plus:
1 2 | https://mail.google.com/mail/images/2/5/pebbles/rocks_tile.jpg */images/2/5/pebbles/rocks_tile.jpg /*wildcard version - for Google Apps*/ |

Refresh Gmail, and it's gone:

Other blockable backgrounds (some of the themes are day-of-the-week specific, so I'll add more to the list as I find them):
1 2 3 4 5 6 7 8 9 10 11 12 | *images/2/5/pebbles/rocks_tile.jpg *images/2/5/mountains/mon/* *images/2/5/mountains/tue/* *images/2/5/mountains/wed/* *images/2/5/mountains/thu/* *images/2/5/mountains/fri/* *images/2/5/mountains/sat/* *images/2/5/mountains/sun/* *images/2/5/tree/sunny/header_bg.jpg *images/2/5/ocean/weekdays/weekday_header.jpg *images/2/5/planets/base/star_tile.gif *images/2/5/planets/saturn/saturn.jpg |
Gmail introduces custom themes (awesome)
Gmail has added the ability to edit your own custom theme-colours. Click on settings -> themes -> "Choose your own colors" which then opens a window where you can edit colours. The changes can be saved and seen immediately.

Example:

Gmail adds themes

The Gmail team have started rolling out theme-functionality. They haven't rolled it out to all users yet, but everyone should have it in a few days.
Go to 'Settings' -> 'Themes', and you'll be able to select a predefined theme.
If you're happy with the default theme - even that has been improved and tweaked slightly. You can also try out the old-school, terminal-style Gmail theme.
Sweet!
WordPress theme: Lounge-blur
I've started designing WordPress themes, this is the first of a few on the way.
To download/preview the theme, click here:
It's a 2-column theme, with a horizontal navigation bar at the top and a simple side-bar on the right. It also has a subtle shadow around the box.
Let me know if you decide to use it or if you find issues with it.
