Most non-MSIE browsers identify themselves as MSIE through the CGI environment... so everyone that thinks MSIE has such a large % of the market -- it's not entirely accurate...
For example in Opera the default setting is "Identify as MSIE 5.0" -- otherwise you can't hit banking sites etc. or they will say "sorry your browser is not supported..." I can understand why banks do this -- they can't afford to provide support for multiple browsers...
Anyway
