I've been using Firefox since...before it existed and was called Mozilla! Although I am late in posting this, Firefox 1.5 was released November 29th.
For those of you who don't know what Firefox is (a web browser, a replacement for Internet Explorer, your best friend[sad but true, admit it!]) you can read this post which discusses reasons for switching from IE. Did you know that the % of users that use IE has dropped from 85.8% in January of 2002 to 73.5% in November 2005. The percentage of Mozilla/Firefox users has grown from 0% in January 2002 to 22.2% November 2005 (see here for data). This may not seem like a lot but considering that IE comes pre-installed on 90% of computers used to browse the Web (same as previous reference but further down) it is remarkable. Firefox is also built by a non-profit organization with virtually no advertising dollars. The reason, therefore, for its growth is the positive press it has received in the industry and through word of mouth.
There are other reasons to use Firefox, and thereby support, the Mozilla foundation who created Firefox. Monopolies stifle innovation, give inordinate power to one organization and allow them to inflate prices beyond what is reasonable. The rise of Firefox has pushed Microsoft to, for arguably the first time since IE 6 was released in 2000 [I think], improve on IE's functionality in it's next release scheduled for 2006. Mozilla, has put out two browsers and new incremental versions, each of which had new and useful functionality in them, since 2002.
Competition is a good thing. Encourage it by adding yourself to the statistics of those who use Firefox and watch the numbers rise.