Question : Flash device Operating System

I'm getting into creating devices that run an OS on a flash/solid state drive. I'm not sure where to start.

For example, I would like to be able to put a lightweight Linux or some other open source OS on a flash device/drive, so that the device can run and listen to ports, or monitor signals, and connect to the internet.

Can someone point me in the right direction? Let's say I want to put this device on a bicycle (a fictitious example), and through battery power I can send signals to this OS and then wirelessly connect to the internet and send HTTP requests with data.

Sounds simple, but I have no idea where to start.

Answer : Flash device Operating System

what are you entering in, the IP, DNS name?  When you say setup open relay, are you talking about a printer sending scanned documents via email?  What are the particulars?