I just spent about 30 minutes fighting with Visual Studio 2008 and JQuery 1.3.2 trying to get Intellisense working in a separate javascript file.  First I followed the Scott Gu post but must have missed the part about adding the ///reference tag.  I found the answer on StackOverflow.com but ran into a problem updating the JQuery intellisense (CTRL + Shift + J).  It said "Warning 1 Error updating JScript IntelliSense: ***** Object doesn't support this property or method @ 2139:1 ******."  I looked a little closer at my solution and the .vsdoc file I downloaded from the offical download page had a .vsdoc2 extension.  Goof?  Anyway, as soon as I renamed, it all started working.  JQuery Intellisense is a huge productivity increase, just a really hacky process getting it to work it seems.  Hopefully VS 2010 will have better support.  Cheers.