[raldi]

The worst is when you write a big long comment, submit it, and get "this link has expired" -- then you hit back, and the textbox is empty.

This is particularly infuriating on a cellphone.

One quick fix: in the code that prints this message, check to see if the request was a comment-post action. If so, append, "...but for your convenience, here's the text you tried to post, so it's not lost forever: [...]"

(Just watch out for XSS!)