“Google’s monopoly power is less threatening than Microsoft’s because changing operating systems is hard, while changing search engines is easy…” – Blake Ross, co-founder of Firefox in his post Tip: Trust is hard to gain, easy to lose.
Interesting read.
(Update – 7/21 /2009 – updated to Internet Archive – http://www.blakeross.com/2006/12/25/google-tips/ no longer is live.)