Sending an analogue signal: Microphone jack or USB?


I know I posted in arduino- but I was wondering if it was possible to not use an arduino at all and just use the minimum components for the smallest form factor possible.

I am extremely inexperienced~ but this is what I would like to do in a nutshell [The methods to my end goal are what I'm trying to figure out]

I want to take an analog input, amplify it [x100 - I can do that using 741's etc.] let's say to a range of -5 to 5 volts [This could be different]. I then want to get that data from the analog signal onto an android phone for me to analyze.

The question is how do I get the data onto the phone?

There are two physical options here I believe.

Option 1: use the microphone jack component to send the signal to the phone

My concerns on that is that it would be a low frequency signal 0 to 4 Hz [Does that matter?] I'd like to actually see the analogue wave and I don't know if that's possible. Do I need to convert the signal into a bit stream using an analog to digital converter? How would I power the IC's to amplify the signal? EDIT: The IC's use very low power and could be powered by the method described here [Playing music]:

Option 2: Use USB. This to me seems to be the much more complicated one. Using android with arduino to communicate via usb: usb android api:

This option seems much harder to do without using an arduino and I am unsure how to approach it. I am really going for minimal size.

I'm just looking for general guidance for a complete newbie. If you would like to provide more helpful info that is up to you! :)

Hmmm It seems like it might be easier to just use USB for power and communication.

All I want to do is just send a signal - no need for it to be two way. Is there a simple way to do this without a micro controller? Or a very very small microcontroller?