Yesterday's very quiet release of updated firmware for the iPhone seems to be operating very smoothly. Apple's release of the 2.21 firmware came accross via iTunes as an unexpected update and gave very little information about what "bug fixes" it was referring to about the changes it would perform. Strangely, even Apple's own website shows 2.2 as the current release, not the 2.21 update. The iTunes update also claimed that Safari will be more stable and that the release fixes a bug in the camera roll.
Whatever the case may be, the 2.21 release seems to be working quite well. My iPhone has had numerous lag issues when scrolling through contacts, web pages and messages. Some lag times were as high as 2 seconds when trying to bring up a contact after touching their name. These longer lag times caused me to think that the screen had not registered the touch and after pressing the screen again made for unfortunate selections or dialing the wrong phone number. 2.21 seems to have cleared this issue up very neatly and the iPhone is much more responsive than before.
Folks who jail break their iPhones have reported that this update closes a hole that previously was exploited but I doubt it will take long for them to find a way around it. Some reports of iPod Touch owners having errors while trying to install the update or immediately after installation have shown up on some websites. Both of the iPhones I updated, a 2G and a 3G, went off without a hitch and are working well.
While there are no earth shaking new features, just a big bunch of patches, 2.21 is a must for any iPhone user.