Another fun fact: Chatty/mmsd-tng doesn't limit you to what file type you send/receive over MMS, provided it is under the attachment size limit. However, if you send wacky file attachments to iOS or Android, they won't recognize it due to limitations on their end.

If you are really adventurous, you can change the file attachment limit in mmsd-tng too (you need to hand edit the settings file).

(Carriers may impose a limits though, so YMMV. I only tested on T-Mobile USA).