OK, so I'm also working on a Spell Index. I sometimes use a great character sheet from here, and they have good dynamic spell sheets as well. I asked politely about sharing the database for these spells, and was refused, so I figured that since I am provided the information in PDF format already I could just use that.
UPDATE (05 June): All spells for Wizard are now available, including the newest from Secrets of Sarlona. I need to work on the search parameters now to get it to be truly useful, but at the moment you can still do a keyword search and a few other things.
UPDATE (25 May 2008): You can now save a spellbook and load it again later.... very handy for coming back to update it when you get some more spells!
I didn't really like the feat index on the Wizards site (and having to scroll all the way to the bottom to learn what sort of bizarre short form Wizards had used to identify their books), so I took it and made something that I like better. It can sort by book, which I find handy. It's on the right bar, in Other Content, called TG.com Feat Index.
NOTE: Updated May 15 with latest additions to WotC list. NOTE: Updated August 12 with the latest additions (MM5 and Shadowdale)