I came across this while looking for an android app for access to forums.
I open the Security Key app, then holding home key I'm able to swap between browser & key app without issues (back and forth as required, I can only remember four numbers at a time). I can login without issue.
Ideally, if we had an android app to access the forums (that would automatically grab key from security app) that would be awesome! Understandably, this requires development i.e. money.
At minimum there should be a 'copy' option so that it can be pasted from the security app to a web browser. That should be easy enough to implement.
Oh ya - I've got a galaxy s2 as well - it rocks - can't wait until Ice Cream Sandwich release