Are there any simple, zippered “sleeve” cases for the iPod Touch

I don't know for sure whether the fourth generation iPod actually has a built in FM Tuner. However, external FM Tuner adapters are quite prevalent.

Edit: Whoops, sorry about that, I did link the wrong item. Chops is correct, that was a transmitter. The link now points to the original item I had intended to link.

• If you're using Windows, you're basically locked into using iTunes to manage your content; some people don't like iTunes.
• Syncing non-media content is weird, too. There isn't a unified sync system. I sync calendar via Google Calendar, notes via SimpleNote, and general files with Dropbox. Some apps only sync with your computer over WiFi, which is a hassle for me at work where the wireless network is not set to permit this. Sync is really important for the iPod Touch because it's nice to have a lot of your data at hand all the time, but it's a pain to type it in manually because it's so small.
• You can't easily update podcasts on the device. I couldn't sync for one week one time and had to update each episode by finding it in the iTunes store.
• It's really smooth, so if your hands are greasy it's easy to drop. Mine has handled drops well. I'm glad I use plastic screen protectors, though.

These are the most potent drawbacks I could come up with. I haven't found any comparable devices that solve these problems any better, though. Non-phone smart devices that fit in your pocket that aren't iPod Touches basically don't exist now; there are some Android devices in the works. I'm delighted by my iPod Touch and absolutely recommend the device.