When I first read Scott's post on it, I decided to give ISAPI_Rewrite a try. I've been thinking for a while to re-direct the end-point of my blog from
http://lozanotek.com
http://www.lozanotek.com
to
http://blog.lozanotek.com
Why? Well, I've always been a fan of subdomains that define a purpose rather than the typical /InsertYourAppNameHere. Technically they're the same, but it's just nice to "package" your web application under it's own subdomain. I mean, come'on, you spent the time working it, why shouldn't it have it's own spot? Remember, when you buy a domain name, you buy *.mydomainnamehere.com not just the www subdomain.
I agree with everyone that has used ISAPI_Rewrite, it's pretty easy to setup and deploy. The regexs for the redirection of the requests are actually not that bad. My httpd.ini is about 4 lines long and things are just up and running fine. This ISAPI filter is a great product!