When dealing with IE7 support I ran into this awesome article: CSS3 Solutions for Internet Explorer. The great part is that the article not just covers everything I needed at that time and even more but also has embedded demos and describes possible drawbacks.
Without copy-pasting the whole article here is what covered there:
- Opacity / Transparency
- Rounded Corners (border-radius)
- Box Shadow
- Text Shadow
- Transparent Background Colors
- Multiple Backgrounds
- Element Rotation (CSS Tranformations)
In addition for those who has to deal with thorough IE support there is another article which outlines How To Create an IE-Only Stylesheet.