I'd also like to be able to add something where you could do this:
% jlj -reply 8675309where you can reply to a specific entry, so for those of us who get mail with the "reply to" url in the body, we can make nifty mail filters to snag out that message id and bring you right into the client. So, for example, if you use the "mh" system to read mail, you could write a script "repl-lj" or something wich will take your current mail message, and let you reply to it in your client.
I have the beginnings of preliminary support in an unreleased version of my client but, once i realized it would require snagging and parsing through webpages, i pretty much scrapped the idea for a while. (It's possible, and not too challenging, but it'd be a pain to do, and i'm lazy.)
I thought it was a cool enough idea to share...