Hi Ivogalea,
well you can install the Smartphone version on your imate Smartphone since the Smartphone version is actually WM5 ready!
(Just the current PPC-version is just running with some constraints on WM5 devices...that's what LordBritish was talking about).
So please check with the Windows Exporer the SiDiary sub-folder "install\Smartphone" this includes all that you need to install the app directly to your phone! (There's a short readme-file too!).
Actually you just need to copy the cab-file to your mobile and execute it within the Pocket Explorer. Then copy the Exe to the folder on your mobile and repeat this with the language files that you want to use.
Unfortunately the installation screen has some constraints: I have received my brandew smartphone last week Thursday and I wasn't able to install it on my first attempt (but I haven't configured the ActiveSync connection, which was still asking for some details). After having configured ActiveSync4.0 I was able to install the device and now I'm using my log book with my smartphone again!
Cheers, Alf.