[darryl]

Last I looked the Kobo H2O was running a variation of Linux, not Android. Aldiko is an Android app and will not run on the H2O. Unless of course you want to run Android on your H2O, which I do recall seeing something about, but doubt it would be as functional for ereading as your stock H2O. At the moment there does not seem to be a way of achieving what you want to achieve. Your best hope is that someone cares enough to hack the H2O firmware to support third party sync, which I doubt will happen.

Sorry to be the bearer of bad tidings.

EDIT: Forgot to add you could try KOReader, which has versions which run on the H2O and on Android. I did play with it for a while and it is excellent software which runs well on the H2O. Last I used it the Android version was not as polished and mileage varied from device to device. But I believe it will synch between KORoeader installed on different devices.