Lefty, the Streak is not unlocked for use on networks other than AT&T even if you bought it out of contract. Officially, you cannot put the Android 2.1 update from O2 on an AT&T Streak, and no plans have been announced to release 2.1 in the future for US customers. It has been widely assumed that the next update to AT&T Streaks will be to Froyo (2.2) directly and that has supposed to be out before the end of the year.

I bought my Streak direct from Dell, and it was unlocked. Stuck my Vodafone SIM in, and it just worked.

I'm also waiting for a 2.1/2.2 upgrade for the direct from Dell Streaks, since we were told that it would be coming.

Well the update is here, sort of. If you go to your about device, cliuck system updates it will rush off and find 85MB of firmware update. It'll spend about 5 mins installing it (there's the clue, it should apparently take 15) and then it will reboot and you will be left with - 1.6.  Just like it was before you started. Good eh?!!!

You're lucky. I received the upgrade notification earlier today - backed up contacts etc to SD went ahead with upgrade option. Download only took 5 to 10 mins then the '15 minute' upgrade started with an on-screen picture of a box apparently emptying into a Streak [presumably to indicate that something was happening] a few minutes later I checked back and the screen was just displaying the Dell 'splash' logo - and here it remained for 15 - 25 - 35 minutes. Decided to re-boot but none of the controls worked. Removed battery - re-inserted - hit start button - Dell logo displays but it's stuck - can't even revert to 1.6.. Has anyone else had this issue - does anyone know of a solution ? I will need to wait until next week when Dell phone support should be available on Monday - fingers crossed !  Phil   :-(

Try the procedure found here:

http://android.modaco.com/content/dell-streak-streak-modaco-com/317240/fixing-streak-bricked-by-the-o2-update/