UPDATE (06/26/2009): In the meantime, another, major problem has been found out: the encoding lag.
This means if you play back any kind of video (either streamed – including YouTube – or local) using A2DP (stereo Bluetooth), the sound will be only heard about half a second (!) later than the video. Yes, the lag introduced by the A2DP encoding is THAT bad.
Give for example
THIS clip a try. Pay special attention to John Krasinski’s short sentences (“right” etc.)
Unfortunately,
this makes watching videos via A2DP almost completely useless. Needless to say, I’ve never encountered anything like this on competing, alternative mobile platforms (at least not on Windows Mobile). There, the engineers paid attention to synchronizing the video with the A2DP audio – unlike at Apple. Bad, very bad, Apple! Programmatically, delaying video playback couldn’t have been THAT hard...
If Apple doesn’t fix this, I’m afraid
we’ll have to wait for video players with settable audio/video synchronization / lag settings to be released. For example, the very famous CorePlayer, which
is slated for July-August this year (hope it’ll really be released – after all, it’s been promised for the iPhone well over a year…) – for a Cydia release (if Apple won’t let it into the AppStore). Too bad the YouTube support of the current, 1.3.2 version on other platforms is definitely inferior to the iPhone YouTube client, particularly in OS3 where you can read the comments / enter comments, can have access to your YouTube account and can see the other videos uploaded by the same user – all this isn’t possible in the (again, current) CorePlayer.
In the meantime, all you can do is going straight for a pair of headphones that comes with a 3.5 mm stereo Bluetooth dongle. The one coming with the BackBeat 906 (which, otherwise, also receives my highest recommendation because it doesn’t have any kind of Wi-Fi interoperability problem, unlike several other models) introduced much less lag than the native A2DP encoder of iPhone. The lag is certainly visible – but in no way as bad as with the built-in A2DP. Fortunately, the dongle has been made with the original iPhone in mind; this also means you won’t have problems connecting it to the 3G either if you have a case on it. (For example, I use the SwitchEasy Capsule Rebel case for my 3G, which, basically, only lets you insert the original 2G/3G headphones. The dongle coming with the BackBeat 906 inserts into the jack without problems.)