You might be interested in my collection of small screen UI design resources at: http://www.paulhibbitts.com/small-screen-ui-design-links.html

Barbara Ballard has started a great wiki which lists plenty of resources for designing and devloping mobile applications and websites.

http://patterns.design4mobile.com/index.php/Main_Page

Good intros:

• Smashing Mag's Mobile Web Design Trends For 2009
• Nielsen's Mobile Usability

Blogs that I know of:

• Adaptive Path's posts on mobile UX
• Sender 11

iPhone related but still relevant. Mainly about how mobile UI is still generally bad and probably much easier to learn what not to do at this stage rather than the opposite.

http://37signals.com/svn/posts/1128-learning-from-bad-ui

2.2) Patterns-Related Resources (cont'd): iPhone OS Reference Library (includes UIKit): http://developer.apple.com/iphone/library/navigation/index.html

3) Other Resources & Articles:

3.1) Designing and building mobile applications and websites (includes a list of topics that may be helpful to get you started in mobile design): http://patterns.littlespringsdesign.com/index.php/Main_Page

3.2) Mobiforge (Resource for mobile web development and mobile web design): http://mobiforge.com/

3.3) Re: iPhone Application UI Design Patterns: http://flyosity.com/application-design/iphone-application-design-patterns.php

3.4) Webcredible articles tagged with 'Mobile': http://www.webcredible.co.uk/user-friendly-resources/mobile/

BlueFlavor produced this guide for developers a couple of years ago which is well worth a read http://blueflavor.com/our-work/dotmobi-developers-guide/

This site will only let me post one hyperlink since I'm a new user here so I'll try posting a few seperately:

1) Best practices: o W3C Mobile Web Best Practices 1.0 (dated 2008): http://www.w3.org/TR/mobile-bp/

Feb 16/10 update: There is now also a set of "flip cards" for the above.

2.1) Patterns-Related Resources:

Jennifer Tidwell - Mobile Design Patterns: http://library.ixda.org/node/20

I thought that this (http://www.boxesandarrows.com/view/four-key-principles) recent article at Boxes & Arrows provided a good analysis of mobile user experience. The thoughts about our intimate relationships with out devices was quite interesting.

I also tend to go back to this (http://www.informationweek.com/blog/main/archives/2007/04/google_lays_out.html) article about Google's mobile UX strategy when thinking about mobile. It's a few years old, but provides a good framework for thinking about mobile tasks.

For apps, check out the iPhone Human Interface Guidelines http://developer.apple.com/iphone/library/documentation/UserExperience/Conceptual/MobileHIG/Introduction/Introduction.html

That's hardcore.