101 things that the Mozilla browser can do that IE cannot is an article which I hope needs no explanation. I feel weird posting all of these anti IE links, because to be honest, I still use IE. I've played with Opera, and I've played with Firefox, and yes they all seemed a lot faster, yes they all have better implementations of CSS, yes they both have better security etc etc, and yes tabbed browsing is very cool - but at the end of the day when you're developing for a corporate audience that means that 99% of your audience is using Internet Explorer, and it does happen to make life easier if you do too.
This is something of a catch 22 situation, but for now I'm going to avoid thinking about it too much and just keep on pasting the links. If I was more disciplined I'd be using IE for all my 'development testing', and Firefox (I prefer it to Opera so far) for my personal browsing.. how many more security paranoia postings it will take to get me to this phase, who can tell.