The best place online to listen to online police scanners is onlinepolicescanners.org. Listening to the police scanner online should not damage your other scanners.
Police scanner let's you listen to police radios and NASCAR scanners are scanners that let's you listen to NASCAR team chatter
radioreference
If you want to listen to police scanners for free, download free online scanner from the link below. This program is free, therefore you can't control the scanner but you can find one close to your area to listen to.
Specialty hobby and electronics stores such as Radio Shack carry police scanners. Additionally one can buy police scanners online from ScannerMaster and Walmart. There are a number of apps for smartphones that also act as police scanners and many local jurisdictions are now broadcasting their emergency channels over the internet as well.
There are lots of places to listen to scanners online. You won't be able to hear lots of big cities, due to Digital Frequencies, but you can listen to Countiy, and township calls usually. Go to places like www.radiorefrence.com and select your state and county. there should be an online scanner for your county.
Stringers
For something like a police scanner your best bet is Radio Shack, either online or in store. If you are more interested in documents scanners then there are numerous places online and in person such as Staples where you can find them.
police scanner download
Police scanners check for police radar beams so that a person knows whether or not they are being monitored. A computer scanners scans a physical document and makes it into a computer document.
One can find police scanners when one goes to a store called Scanner Master. This store carries police scanners made by Uniden and Bearcat. Price varies by brand and model.
Try the Radio Relay website (see related link at the bottom). I know I was able to listen to Johnston County on there (as well as Wake, Durham, and Orange), so I'm pretty sure Onslow would be on there, as well. At a very minimum, you should be able to get something from Jacksonville.
The Police Scanner 5-0 app for Android is completely free of charge and has online ratings of between 80% and 100%. This is clearly one of the best police scanners currently available. Police Scanner 5-0 can pick up most digitally broadcast police frequencies.