Some good news, some bad news for iPhone/iPod Touch owners. (For everyone who doesn’t care, we’ll be consolidating iPhone news from here on out so you can safely ignore it.)

Good news: iZotope’s mobile version of iDrum is here (seen above). It’s a nifty $5 toy, though some restrictions, including the lack of audio export, may keep it from being more than that.I Correction: you can exchange both samples and project files with the desktop iDrum, and use ringtone bounce (including, apparently, on iPod touch) to export audio. That could make this very useful as a mobile addition to your workflow.

I do also think it’s inspiring in the way that it uses touch interfaces, something that could bode well for what touch-enabled computer music apps might look like.

Better news: BtBx is a fun-looking US$3.99 beat machine with drum sounds and (at last!) real-time synthesizers from the creator of PSP Rhythm. Unfortunately, it doesn’t let you use your own samples, and it can’t quite stand up to the cooler PSP Rhythm – even if hacking a PSP is kind of a pain. But it is a good sign.

But bad news for Apple owners, good news for owners of other gadgets: the generative music studio Mixtikl will hit those platforms first because of Apple is tying its developers’ hands with technical and legal restrictions. It’s not a deal killer for everyone – we’ve seen developers write special client apps to get around file exchange issues, and obviously a number of developers aren’t concerned with legal terms because they’re releasing apps anyway. (Jobs is justifiably proud of their 60 million-download count.) But there’s no question that part of why the iPhone is more a mobile toy and less a mobile computer is in fine print and legalese, not silicon. That could be mobile carriers’ fault – but either way, it could also demonstrate that shrinking computers and not more powerful mobiles are the future for mobile music creation.