Here's a list of the ones I've done so far:
A: "After the War", "And Then There Was One", "Absence".
B: "Behind a Frowning Providence He Hides a Smiling Face".
I: "In the Morning".
M: "Moving On".
R: "The River".
T: "A Toast".
W: "Winchester's Conversion", "A Whisper".
Hmm. 14 fics for 11 letters. "F" is the only one I can't find a copy of, so I don't know if I've spelt it with the correct number of vowels. [Edit: Now found, and linked above.] I've omitted definite and indefinite articles at the start of titles, for the purpose of choosing a letter.
If anyone spots one of mine I haven't listed (I'm not very organised) then please let me know.
Crossposted to the "mash-slash" Yahoo! group and to mash_slash.