It was good while it lasted.
After a week I've hit the bandwidth limit (1GB a month) on the free Screencast.com trial account provided by Jing. While it is possible to upgrade to a paid account, this is rather pricey, especially considering Jing is still in beta. There are workarounds, such as saving a Flash .swf file, uploading it to a server, rolling your own embed code and then posting the whole thing, but this totally negates the point of Jing, which is "point and click" ease of use. I plan to continue using Jing for student feedback (Jing will save screen captures as .swf files which it's easy to upload into Blackboard), but there won't be any more Jing posts here, so I guess it's back to Snapz Pro X (or your favourite screen capture application) and YouTube for blogging. Sigh.
On a brighter note, I do seem to be making progress on the Ubuntu front, and this morning I installed Kompozer, which is a more advanced version of nvu, which frankly I had been struggling with (thanks for the tip Ray).