More than end-user functionality?

Some generic LG "smartphone" similar to an iPhone (touchscreen)
Uses Android OS (?)

My friend switched a Blackberry last Xmas and I asked him if he wanted to sell the smartphone he is no longer using. I have never used a smartphone primarily because they come with inflexible and expensive phone plans attached or they are horribly over-priced.

People may think I am a cheapskate but I'll tell you what I think when I think about paying unnecessary mark-ups. Imagine you are an actor looking for high-end cocaine... you don't want to pay poor people prices so you go to the dealer with a bag of baking soda and a plastic baggie with "Hollywood Elite" written on it in sharpie and insist on paying ten times normal because you do not want to appear to be poor... this is the image I get whenever I consider paying moar for hardware than I absolutely have to. ( I am not attempting to promote drug use ... in fact I find that almost all drugs besides caffeine cripple my computer skills and not enhance them ... is just an example I find to be unambiguous )

Back on task... I already have a Skype account and online number so the $50 I am going to pay for the smartphone is already a good investment since the usb skype phone I bought earlier is less than impressive.

Actual Question: Since Android is Linux-based can I squeeze moar functionality out of an Android phone than the typical end-user would need?

I would have asked this question on Androidquestions but I imagine the skilled hackers here would be better suited to answer the question.

I know the question is kinda open-ended but try to think of a functionality that a pen tester with a fondness for designing networks would find interesting. Stuff along the lines of being able to pick up commercial AM/FM bands... I find making hardware moar versatile than intended to be fascinating. Z/Z

The big thing would be sensors. PCs don't really have any, and smartphones are stuffed full of them.

Next, location and communication. You can move the device around easily and setup wireless APs, bluetooth pairings, etc.

Also, you can use the thing to do some embedded development on ARM, which could be fun.

Thanks. The ARM thing is interesting but I am not sure if any distro does one designed for iphone-esque devices with touchscreens. Z/Z