It's possible I might not be stuffed though, for two reasons. One is that I might be able to split my request in two: send the metadata first, get a file ID back from the server, then send the actual file across, using the ID so the server knows where to put it. But from the code samples I've seen online, I'm not convinced of that just yet. The other is a very helpful tweet I just received, from @mindelusions:
I reckon I'll take Anthony up on that offer, and see how far I get. I should say that this won't stop me using or recommending Titanium, but it is a blow for the "it can do virtually anything iOS can" argument. For instance, what's the point of having the facility to record video if you can't upload it somewhere? It's not like other apps can make use of those files, and Titanium isn't powerful enough (I don't think anyway) to do full-on video editing.
Anyway, it all remains to be seen.