The iphone in the studio?

I recently acquired an iPhone 3G. Before I had my hands on one, I had heard about and seen videos of things like apps that control Protools or others DAWs and thought; that's a gadget, why would anyone want to do use their phone as a control surface?
So, when I received the iPhone, I did not have any expectations of using it as a music tool.
I have been pleasantly surprised!
One of the first tools I bought was Cleartune. This is an excellent tuner that has a transposition feature, temperament options and selectable pitch-pipe wave forms. It has been super handy to have a tuner in my pocket.
Another app along the same lines is SPL Meter by Studio Six Digital. I like the analogue style VU on this one. It has response and weighting options as well calibration and can use an external mic as well.
An app that has really surprised me is Ocarina. If you are a musician and have not seen this one, I am just gonna say "check it out". Either on youtube or download.
Another big surprise (the iPhone is just full of them!) are the synths that are available. Again, you see all the piano apps and think; "gadget". I mean, you can only get an octave on the screen and even then, the keys are tiny, right? Well, even though that is true, I have actually used miniSynth on a session. It just had the sound I needed right at my fingertips ready to go. The latency on this one still needs some work though. What is cool though is that the small screen on the iPhone has inspired some creative interfaces. One of those is Bebot. Instead of virtual keys, you can set the increments and intervals on the screen and slide or press each note. It's pretty darn responsive (it's a phone for crying out loud!) if you like synths, I recommend this one highly. Again, I just used it on a session for MTV. Another creative interface is Bloom. Designed by Producer and Ambient music pioneer Brian Eno- in collaboration with musician/programmer Peter Chilvers.
This is a semi random, ambient music creator. It's hard to describe but the interface is beautifully done and fun to play. If you like Eno's "Music for Airports" this is a must have.
I have a few others, Metronome (cool, old style interface) Chordmaster, iHarmony etc.. but the above are the standouts for me so far. Others may prove useful as time goes on.
Similarly, I didn't really think that I would use the ipod feature much. Dead wrong. It's so easy to download and listen on the go. You have to pay attention to the battery life but, I do that anyway.
I've have realized that the power of the iPhone and all these tools is that they are in your pocket, on one device! Kudos to apple and double kudos to the developers of these fine tools.
So, what is your fav music related app?? Please share!