All that you need is for the two devices to have a route between each other. For example, if both are on the same WiFi network, they should be able to ping each other. Do make sure that any firewall / AV software you have installed will allow access through port 3000.
If, on the other hand, your android device is only on your cellular network, you'd need to either connect it to your existing WiFi (if you have it), or set up an Ad-hoc WiFi Network from your dev machine and connect your Android device to that. There should be lots of instructions online on how to set up an ad-hoc wifi network for Windows 7.
Does that help any?
Thanks for helping!
I cannot ensure that both devices (my computer and my cell phone) ARE at the same network. What I can tell you is that both can access Internet through the same wifi signal broadcast by the wifi router I have in my house. I am not sure that it puts them into the same network though.
Anyway when I start Phonegap in my computer it says that my server IP is 192.168.0.100:3000. Then when I start Phonegap in my mobile it keeps looking forever until time out.
What would be my next step in order to put them seeing each other?
If both of your devices are talking to the same WiFi router, you're on the same network.
What software are you using for Anti-virus / Firewall on your desktop machine?
Also, to help verify connectivity, download a "ping" app from the app store on your device. Then try to ping the IP address (minus the :3000) your computer is giving you. If you don't see timeouts, the two devices can see each other (and the :3000 may just indicate a blocked port.)
OK, I use Zonealarm Firewall and Avast Antivirus on , both free edition. I disabled both (so I shouldn't have anything blocking stuff right?) and used a ping app from my mobile to ping to 192.168.0.100 that's the IP the desktop Phonegap gave to me. I keep getting "Request timed out". What am I doing wrong?
You don't have the Windows Firewall turned on by chance, do you?
Try pinging other things on your network -- another computer, printer, etc., or even just the router from your iPhone to make sure that it can ping other devices.
Nope, Windows firewall is not on. I will check those things.