Lonely Planet is offering many of it’s European City Guides (iTunes Link) on the iPhone / iPod touch / iPad in the iTunes App Store for FREE (regularly $15.99 each) for a limited time. The guides are intended to benefit travelers who are stranded due to the Icelandic volcano eruption but are available to everyone. Features include offline maps, location-based navigation, points of interest, image galleries, and renowned editorial content. Deal expires April 22, 2010.

The FREE Guides (iTunes links below):

• Lonely Planet Copenhagen City Guide
• Lonely Planet Munich City Guide
• Lonely Planet Stockholm City Guide
• Lonely Planet Vienna City Guide
• Lonely Planet Budapest City Guide
• Lonely Planet Istanbul City Guide
• Lonely Planet Moscow City Guide
• Lonely Planet Rome City Guide
• Lonely Planet Amsterdam City Guide
• Lonely Planet Barcelona City Guide
• Lonely Planet Berlin City Guide
• Lonely Planet London City Guide
• Lonely Planet Paris City Guide