The current mobile-friendly theme I am using is called TotalPress.
I like it OK -- it still needs a few tweaks.
My issues with it are:
--not crazy about the light-grey text in blockquotes --
I need to figure out a way to darken it
--it's not as easy to "poke" the CSS as it was with my previous theme. I would like to "comment out" the theme branding in the footer but haven't figured out how to do it yet. [Update: Done, thanks to Rene Abythe for the CSS] Would also like to remove the phrase "comments off" that appears in each post; that seems like a needless provocation for the "no comments means intellectual fascism" contingent. [Update: Done]
--I tested the site on MobiReady and it got a low score. The reasons have to do with exotic web developer considerations that make an OG, HTML-era blogger such as myself want to f*ing hurl. It's painful to read that, in the course of making my site "better" on phones, I've adopted a theme that has the following negatives:
1. DOM element count is high at 938. [Update: I think I reduced these deadly DOMs to under 700, the acceptable range, by switching my Archives on the sidebar to a dropdown. That list was too long anyway.]
2. All page assets should use appropriate Etag headers to enable client-side caching and speed up future page loads -- No Etag header found.
4. HTTP response should be compressed using server-side configuration of GZIP or similar compression technology -- Gzip transport encoding not detected.
For what it's worth, a nearly pure HTML page such as this one also scores poorly on MobiReady.
They are freaked out because it's all images, even though most are in the 100KB range. I'm sure there is some low-res art that would be appropriate for your precious phone but I'm seriously not interested in making it.