I also converted when I bought a gen 1 MacBook Pro. I am a Windows .Net developer and all i say to people it this, "I can burn a DVD, listen to iTunes, compile my software under Parallels, and surf the web all at once without skipping a beat." OS X rocks! Man, I can even watch a movie while playing WoW :)
I've been using a service called Mozy for a few months now. It's works well but I wouldn't use it for backing up my entire drive. Currently I'm backing up about 3GB worth of data and it works well. One day I might get around to putting my iTunes library on it to see how well it works.
Mozy is a service that gives you unlimited space for about $5 a month. A little program runs in the background and you configure it to backup the files that you want to save. It has Spotlight searching which makes it nice for finding specific sets of files.
Occasionally I use Carbon Copy to make a bootable image as well.
Also, from what I've read, Time Machine requires and external drive to do its magic.
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