So when is IE5/Win going to have full support for PNG (Portable Network Graphic) files? This format is far superior to the common GIF format because it generates smaller file sizes, renders more quickly on browsers and supports neato tricks like alpha transparency [which means you can create fancy ‘see-through’ graphics]. At the moment, PNG is the graphic format of choice for Flash developers as the Flash plugin has full support for this format. But for non-flash web designers, it's not looking too good. Whereas Netscape 6* [for all platforms] and IE5/Mac does have full support for PNG, IE5/Win doesn't - which means it will be a long time before PNG has its day [and it's been waiting for about 4 years].
For more on PNG, read:
Whatever happened to PNG? [Webmonkey]
The Story of PNG [slashdot]
*OK… so Netscape 6 is particularly bug-ridden, but in my opinion, it is the second best browser out there after IE5/Mac.