I just noticed the new Rick Steves iPhone apps available. Sounds like a good idea. They currently only have apps for France and Italy. The tours cost $4.99 each. The Orsay Museum Tour is free during the month of July 2009.
Here's the posted description...
Rick Steves' iPhone Apps are personal tour guides for your iPhone or iPod Touch. These interactive, multimedia guides will lead you on walking tours straight from the pages of Rick Steves' best-selling travel guidebooks. Numbered points on the map correspond with recommended tour sights. Spin the compass icon to switch views between sights, hotels, restaurants and WCs along your route.
Tap any point to read Rick's detailed information on the sight, including history and suggested viewpoints. Tap the Info tab of any sight, hotel, restaurant for more details — including cost, hours, address, and phone number. The zoom feature on the interactive map helps you get a closer view of streets, landmarks, and other points of interest.
A pull-down audio player lets you listen to Rick talk about each section of the tour, and videos provide more detailed information about the sights.
Once downloaded, these Rick Steves apps are completely self-contained on your iPhone or iPod Touch, so you won't incur pricey roaming charges in Europe.