I\'d been reading up on themes in my ASP.NET book and thought that it could be a very handy solution, then I met some problems.
IMHO, asp.net themes are absolutely USELESS
try implementing url rewriting with an app which uses themes and see them break straight away
basically, you can achieve the same thing writing few lines of code in asp.net and multiple css folders. i am yet to come across any developer / company who has been using themes
when asp.net 2.0 was launched, there was a big hype around themes but my personal opinion is its simply not worth it :-)