We talk a lot about tweaking your user interface around here—often inradical ways—but if you'd just like to make a few small tweaks to Windows Aero, free app AeroTuner gives you a few more options than the Control Panel.

Windows: AquaSnap is a free multifunctional tweaking application that brings Aero-style effects to Windows XP and enhances Aero in Vista and Windows 7.

Reader t.click's desktop sports an amazing, totally transparent skin for the Opera browser that uses Aero Glass to render virtually the entire interface.

If you've been disappointed by the lack of Aero-based visual effects when you install Windows Vista or Windows 7 in a Virtual Machine installation, this handy guide will help you crank up the eye candy in your Windows virtualisation.

Windows only: Mozilla released the mockups for the far-in-the-future Firefox 4.0 release, and just like with the 3.7 release mockups, a motivated user has already created a lookalike theme that you can install now.

Windows only: customisation utility Border Skin adds the Aero Glass effects from Windows 7 or Vista to your PC running XP.

Last week we took a look at initial design mockups for Firefox 3.7, and now the busy designers at Mozilla are back with some theme mockups for the even further-into-the-future Firefox 4.0.

Windows only: Mozilla released their version 3.7 theme mockups only a few days ago, but you don't have to wait—a motivated user already released a lookalike theme that you can install now.

Firefox 3.5 was officially released late last month, but the Mozilla team has already released its initial Windows theme mockups for Firefox 3.7, featuring glossy, translucent buttons and a host of other potential new features.

Windows only: Application launcher 7stacks adds the Stacks functionality of Mac's OS X to Windows 7, including Aero transparency effects that blend into your taskbar perfectly.

Windows only: Glass Notepad extends the Aero transparency effect to the entire editing window—a slick replacement for the built-in Notepad utility.

There's been plenty of buzz about Windows 7's great new Aero Snap feature—and reader John makes it better with a tip to maximise windows vertically with nothing more than a double-click.

After we wrote about the All-Glass Firefox theme, reader bc//G_A wrote in with an even more impressive customisation that enables the Aero Glass effect across almost every UI element.

Windows only: All-Glass Firefox v2 extends the super-slick Windows Vista Aero transparency effects to almost every piece of the Firefox interface.

Windows only: Tiny application Glass CMD for Vista forces command prompt windows to use Aero's glass transparency effect.

The default Firefox theme doesn't match Windows Vista very well—but with a few extensions and a Stylish script, you can customise Firefox to use a slick, well-integrated look with Vista Aero transparency effects.

Sibling site Gizmodo rounds up the most noteworthy interface and productivity-minded changes in the Windows 7 Release Candidate. Most relate to Aero Peek, the taskbar, and other interface changes, but there's also some User Account Control tweaks and new keyboard shortcuts. Got a suggestion for the Win7 developers on what else should change?

Windows Vista (with Aero running) only: Wheelie, a free beta app, can be used solely as a pretty neat application switcher at this point, but its developers seem to have much grander plans for the little utility. Once installed, you can flip through active window thumbnails with your mouse wheel by touching the top edge of the screen. Park the cursor there, however, type in a word or phrase, and your screen fills with results from (apparently) Google Image Search. It's important to note that Wheelie takes up a serious chunk of memory in its current beta state, but it's an intriguing experiment that at least offers an alternative to Alt-and-Tab-ing at this point. Wheelie is a free download for Windows Vista systems running Aero only. Wheelie

Windows Vista's Aero looks and effects are generally nice to look at, but when you're trying to squeeze the last bit of power and life out of a battery, or just running some memory-hungry stuff, you don't always need them. Windows Vista Magazine details a registry hack you can make to add "Aero On" and "Aero Off" shortcuts to your desktop right-click menu, making it simple and quick to toggle the fancier stuff (it's the second major tip, about 1/3 down the page). We've already shown how to disable Aero for particular programs, but this trick might work better for working on the go, gaming, or other situations where you need to cut out the whiz-bang stuff. PC Heaven