I will qualify this. If you are a programmer used to an IDE, Arduino sucks. It wes made to allow painters, breadmakers and other artists to make embedded elements, and maybe for a non-programmer, it may be the only (and best) thing out there.
I tried this and dropped it fast. Instead I ended up using Code Composer Studio. It works like a charm for all TI's boards. Try out the 430 development system on sale for $4.30. Great IDE with in circuit debugging and all the other features you are used to, and you are up and running in no time.
Android is also a good choice, powerful, but a little different if you are used to C/C++ insted of Java. Not only for phones but a lot of other embedded devices as well.
BTW, You can get used Samsung Galaxy with a new battery for $100. It is an incredible embedded device, and if you want buy an Arduino device with even a small part of the features, you will pay many times this.
!GHz ARM, 16BG flash, dilsplay,WiFi, Cameras, Graphics engine, xyz accelerometers, maybe gyros. If you need USB master you have to get android 4.0 based device.