Just in case you start using Joomla 1.7 with Internet Explorer. There appears to be a glitch where the Global Config. will not allow you to save changes if you are using IE. There is not a patch yet that I am aware of. If you use Firefox or Chrome it works fine. I have used almost every version of Joomla, and never ran into this before. Just a heads up.
That is a known problem that unfortunately affects almost all forms in Joomla. The problem has been fixed in the dev version a few weeks ago and the fix will be part of the next update.