Twitter designer finds Facebook for iPhone imitation decidedly unflattering
Seriously Facebook? http://pic.twitter.com/0ifNsdY
Ok Facebook, enough with the flattery. http://pic.twitter.com/vSyHdpH
Though TechCrunch points out Haggerty was at LinkedIn when LinkedIn's mobile app looked a lot like Facebook. Twitter for iPhone is no stranger to flattery, however, as back when it was still Tweetie, it's "pull to refresh" feature was so intuitive it quickly spread to other apps and even web frameworks.
At a certain point, a "best" way of doing something gets discovered and for the sake of consistency and user friendliness, it makes more sense for that "best" way to become a standard. (See Lotus vs. Excel). Whether or not the Twitter photo sharing UI qualifies as something so good it should become a standard, we'll have to wait and see.