Mohtalim

Websites that require IE in order to work like ADP and DishTV and company internal webpages

There exists a Firefox extension for that.

One for chrome too (IE Tab)

Ummm, yeah, that solution is pretty f'ing lame. It still involves actually using IE. That's especially annoying on my work machine where I can't upgrade my version of IE past IE 7 because I won't be able to use some of the HR pages if I do upgrade.

There's a different FF extension to just change the user agent string to IE.

It's not a user agent problem as much as a problem with the page being coded using elements and javascript functions that aren't in chrome or firefox. It's basically the stupid MS incompatibility issues. It's why it's so damn hard to write your own ajax pages and why you should use a library's implementation that already covers most of the inconsistencies of old versions of IE.