Today, T-Mobile finally announced that Android 2.1 (Eclair) was available for G2 Touch (AKA HTC Hero) owners.

If you’ve not received your “pre-upgrade” update already, you’ll need to do this – it makes various small changes in readiness for the Eclair update.

To get this, wind your clock on by a month and switch off wi-fi (it needs the data connection for the upgrade to be detected). It only takes a couple of minutes and doesn’t cause any data loss.

Once you have that, you can either wait for Eclair to be pushed out to your phone or go and get it manually. To do the latter, go into Menu -> Settings -> About Phone and you should now have an option to check for software updates. Go into this and follow all prompts.

Now, the Android update can cause data lose, although I found it to be minimal. I’d recommend backing up all your data – I used MyBackup Pro to backup all data and applications to my SD card, which I then copied into my Netbook.

The update takes a few minutes and, even when it appears to have rebooted, you might find that behind your lock screen is an HTC update running. Once this is done I found my date and time was incorrect and that my home screens had been reset – if you saved your layout as a “Theme” (which I hadn’t done) then I’m guessing you can easily restore it.

And that’s it.

From what I can tell the visible changes are minimal (even more so – animations are turned off by default, so you’ll need to switch them on for the full impact) – the main change is the improvement in speed. And, boy, is it noticeable.

Other than that, the biggest change to users will be the apps in the Marketplace that will now be available – Google Earth, IMDB, Google Goggles, Talk To Me, amongst many others.

Smaller changes include an improved Gmail App, a new pinch feature for viewing all the home screens and a Desk Clock app.