2 browsers installed at the same ime (is it safe)

I have a question.  It it safe to have 2 web browsers intalled on my computer at the same time?

For years I have been using IE6 and then IE7.  Now I have installed Firefox 3.0.4 because its more secure and much faster.

I use Firefox now obout 99% of the  time - emailing, browsing etc.  And IE7 only if I am installing new programs as I find Firefox sometimes doesn't install them.

 

So it is safe to have 2 browsers installed at the same time???     Are there any conflicts,  etc???

 

Thanks