>Live Journal - works
>Blogger - works
>Wordpress.com - works directly from gmail, but haven't had
>success wtih LetterMeLater yet...not sure why.
>Vox - works

Tumblr - works
Posterous - works
OnSugar - works, has RSS widget and/or RSS in sidebar
Multiply - works
Windows Live - works
Opera - works

All worked with LetterMeLater except wordpress.com

Calvin