I've searched but haven't been able to find a direct answer to this.

I was reading a photographers'-rights blog (Photography is Not a Crime) and got to thinking that it'd be a good idea, if possible, to configure my N900 to automatically upload pictures I take with it to some online file store or another. Not too concerned with exactly where, just so long as a copy of the picture is created ASAP at a location immune from attempts at coerced deletion.

I know iOS and Android have the TapIn.tv app to do something similar to this with video (last I checked, it was designed so there was no way to delete footage from the device, again, to protect against law-enforcement trying to force users to delete incriminating video), and I know there's Bambuser and Qik for Maemo, but I haven't seen anything for photos. We have the ability to share from the post-capture preview (postview?) but it requires user interaction and is slow.

I'm wondering if anything exists, either as a standalone program or as an extension to the camera program, that can be preconfigured for uploading and then just cache images for background transfer as they're taken. FCamera can do an offline equivalent (you can "delete" the picture from Photos and the RAW will still be in /home/user/MyDocs/FCamera) but that doesn't help much in the event of the phone being confiscated.

Anyone know of anything like this?

Longwire Pro for N9 will do just that. Maybe you can convince the developer to port to N900.

You could use rsync to synchronize your DCIM folder (where photos are stored) with a server/NAS that supports either rsync directly or just ssh.

I'm not sure if it's possible but did you try with DropN900?