I would like something like an iPod nano/touch with the hackability of a Raspberry Pi (Linux). I don't need the GPIO etc as I'll never be hacking hardware, and I definitely want good battery life. A screen is not important, but a few buttons & some sensors would be nice. Anything like that out there ?
Really depends what you want to do.<p>The Intel Edison kit from Sparkfun has an OLED screen with buttons on it. You can easily add sensors, speakers, etc. It runs Linux and can act as an access point (but not at the same time you use it as a station) so you can ssh in from your phone and do more complex stuff. You'd need an enclosure of some kind but 3D printing is common these days.<p>Another option would be something like the TinyDuino, which has a wearable kit. It's Arduino but maybe it could be made to work.<p>The new Raspberry Pi Zero W would be the perfect form factor but I haven't seen any interesting in terms of wearables, and it runs at 5 volts which is a bit discouraging for this use case.
What is your use case?<p>You are asking for something like an iPod, but the screen is not important. When you look at an iPod touch, the main feature is the screen! I think you need to give a better description of what you are looking for. Is it a one-off project, or are you developing a product?<p>If you want something like an iPod with a touch screen, look at android devices.<p>Otherwise there are add-on boards for the raspberry pi that let you connect a battery.