that 50% isn't working .. That's one of the limitations using DIVS / List instead of tables.. 
It's possible in theory (splitting the lists in seperate lists for each letter) but that requres the width / max-width / min-width attribute for the table-cells which is IMO dirty and is causing issues in responsive view where severals rows may be hidden.

While going to work I had another idea to make it eye-candy without centering the text /Letter.. It's emulating a  tabbed layout

Screenshot:
![mlist](https://f.cloud.github.com/assets/1027992/2354304/516b5786-a5bc-11e3-8b34-ef8c3b0ccd1f.png)
Still needs some code cleaning but I think it's a suitable solution.
Opinions?