Working with Gmail can be a lot nicer if you use a desktop e-mail program instead of Gmail's Web-based interface.
Gmail - News, Features, and Slideshows
I've used practically every Web-based e-mail program, from Hotmail to Yahoo to Chick Mail (seriously), and I have to say Gmail is awesome. But it could be better.
Gmail ushered in a whole new way of accessing and managing e-mail. Many people think that it's a major improvement over the old desktop-app approach.