It seems to me that a common problem with paste type services such as pastie.textmate.org is that it's a one-way street, which is strange considering a lot of people who use the pastie service are after solutions to problems in the text they have pasted.
I came up with the idea of running a service which would allow people to connect to a server, submit the text and then give them a unique ID. This ID could then be quoted to other users and used to connect to the server remotely, grab the text, and view the paste using a TextMate command. Any changes made to the original could then be saved and re-submitted to the server. The original paster can then query the server at any time to review any changes made to the original along with the names of the users who have made the amendments.
I considered starting on a project which does all this using a fancy tm_dialog UI, but besides being a cute idea I wondered if this is a solution seeking a problem rather than something people would actually use?