I just started using ONfree.com (Divers program). Or INfree.com.
I have been able to use it without using their software.... THEY HAVE NO BANNERS though. I use a DUN connection.
However!!! Today I went to their site and noticed that they appear to be charging for the service now! I am still connecting for free though.
You might check out the site. There may still be some free programs.
Also you can check out Freedomlist.com for more.
Good luck.