http://disneyworldforum.disney.go.com/questions.aspx?sort=views&page=1&qid=17342&pid=45&cid=70
Tipping is a personal choice. So, this information below is just what works for me, other levels of tipping may work for other guests. OK, here goes...
1. Prices can change, but valet parking is $10 per day at WDW. There are exceptions to this for Disney Vacation Club members and for Disney Dining Experience cardholders. Parking costs more at the Swan & Dolphin.
2. I tip the valet driver who returns my car $2.00. More if it is raining. There is an EXCELLENT discussion of valet tipping on the website allearsnet.com. Click on the search button (top right) and search for an article called "Valet Parking at WDW." All the rule exceptions are explained here, as is well-considered rationale for various levels of tipping. I also tip the bell desk attendant who gets a cab for me $1-2.
3. The rule of thumb for tipping bell services is a minimum of $1.00 per bag or other item. More if things are particularly heavy. This is true at all resort levels: value, moderate, and deluxe. Also, if a bellperson that assists me when checking in to the hotel provides other services such as pointing out features of the hotel, showing me features of the room, or otherwise helps out in any way, I tip more. I'd say that my family of five usually tips the check-in bellperson $10-15. The check-out bellperson gets tipped $5-10 depending on how many bags we have.
4. We tip mousekeepers $3-5 per day. I wish i could say I had some formula for figuring out the tip here, but honestly it has a lot to do with how many single bills hubby and I have on hand. If you look on the right side of the Moms Panel site you'll see a box that says New Videos for Moms, by Moms. Click there and look for a video by the lovely and talented Heather R called Trip Planning is for Everyone. She shows a great project she does with her kids related to mousekeeper tipping. We usually just leave a note next to the bills that says something like "Thanks for making our room look great" or something to that effect