Thumblogger is in business for over 1 year now and hosting many adult blogs for many adult webmasters, just use google to find out.
If you still want to put your main blog on your own domain/hosting than you can still use thumblogger, just put a couple blogs on thumblogger that feed your main blog. Great for PR and search engine traffic.
Most blogs at thumblogger are spidered within one day and if you put some work in it you will get A++ quality search engine traffic from all major search engines. Look at google again if you don't believe me
There was a topic on NP (on the blogging forum) about traffic on thumblogger, that may interest you.