What I’d really like is to be able to define my own mobile theme.
staff:
Your blogs now comes with an optimized iPhone layout!
And a damn nice looking one at that.
This should be a huge improvement when browsing Tumblr blogs from the iPhone — and we’re building similar views for BlackBerry’s, Android, and more. Stay tuned.
If your theme already looks great on mobile devices, you can disable this feature by unchecking Customize → Advanced → Use optimized layout on mobile devices.
I’ve started converting my Tumblr theme to HTML5. I found a good example of a blog layout from Sitepoint (I know, right?). So far so good, but when I ran my site through an HTML5 validater I discovered that the IFRAME injected by Tumblr contains attributes that are not valid HTML5. Oh well, not much I can do about that.