With the recent announcement of the iPad, there's been a resurgence in the issue of multi-tasking. The iPhone, famously, doesn't support multi-tasking - a fact that Palm were quick to exploit in marketing the multi-tasking Pre. The iPhone can do multiple things at once, but only Apple things, like checking mail, or ringing on an incoming call during your game of Grand Theft Auto. The technorati would have it that multi-tasking is an essential part of any computing device. After all, it was the killer feature of Windows that brought us out of the dark ages of DOS.
The trouble with multitasking is that your hardware has to know how to juggle, without necessarily knowing how many balls or how big each ball may be. To compensate, the hardware tries clever things to re-prioritise the tasks (balls), so that each gets something approximating the resources it needs. This takes time, and requires a certain amount of flexibility on behalf of the task: it may not get all the resources it asks for. A robust app will cope gracefully, a sloppy app will crash. So, with multitasking your mileage may vary.
Now this usually seems a reasonable price to pay for being able to juggle several things at once: copying that text to your spreadsheet from your browser,while it downloads the next page in the background. But on a phone? Do I really need that multitasking enough to risk sacrificing the snappy, consistent response I need from a phone?
I had a couple too many apps open on my Google phone the other day - mucking about with a few newly downloaded apps - and I abruptly had to make a phone call. I pressed the Phone app button and... waited. Probably a full 30 seconds later, one of the other apps crashed, and my phone was usable again. Way too long for a phone to make a call. The trouble is, the phone is just another app on a smart phone, and if the smart phone is multitasking, the phone app has got to juggle and jostle with all the rest of the apps.
The truly smart thing about Apple and their iPhone is a) single-tasking, and b) except where Apple decide multitasking is needed for notifications. And Apple control the latter by vetting every single app to hit the app store. So while some may bemoan Apple's control of apps, I actually think it is necessary quality assurance to ensure that users get a snappy phone that does apps, rather than a micro PC that happens to have a phone app too. This will be the chief hurdle that Android/Google/HTC will have to leap.
As for the iPad, it's an interesting gambit by Apple: their second bite at the tablet market, after the Newton (no, it wasn't a PDA)! This time they have the iStores, so maybe they'll pull it off, but my gut says it's a product looking for a need. I can do all the things on it that I can do on my iTouch, so that just makes it an oversized iTouch, right?