I've got the orientation-awareness working I think (if I can trust the results from the emulator), based on the method used in the WebCrawler sample included with the Developer Resources for Windows Mobile 2003 Second Edition.
I've also implemented a nicely annoying technique for making a tab behave like a modal dialog (sort of) in order to ensure configuration information has been set up before someone tries to post. I spent some time agonizing over whether to use an XML file to store configuration, but in view of the limitations of XML support in CF v1.0 it's actually going to be easier to use name/value pairs in a text file and parse them with regular expression evaluation (I don't think there's anything important missing there...I'll find out soon.)
This has the additional advantage that the text file itself will be easily user-editable, not that that should be necessary.
Up until now I've tended to automatically pop the SIP up whenever anyone entered a text entry area, but I think that could cause problems with hardware keyboards so I'll probably either leave it out or make it a configuration option.