One of the things you should get from Cydia (after MyWi, SBSettings, and VLC), is OpenSSH to let you SSH into your device and do things such as copy movies for VLC to play.
After you get OpenSSH, you’ll notice that nothing happens. Don’t worry, it’s running.
To connect to it you’ll need the device’s IP Address which, if you are on a WiFi network, you can go to Settings->Wi-Fi and click on the name of the Wi-Fi to see the IP Address.
Then type this into your computer Terminal:
Your password will initially be alpine but the first thing you should do is change it, like so:
Now you are free. (as in speech)
If you are on 3G, you’ll need Reverse SSH Tunneling set up, which isn’t as glorious as its name:
Get the pTerm app or some other Terminal app for iOS (either from the App Store or from the forbidden Installous garden).
Type this to set up the tunneling:
You need to keep that connection (and app) open from your iOS device with the Backgrounder App, which will be a battery hog.
On your computer you can now connect with this command:
Again, the WiFi option is the way to go, but if you must connect to it via 3G, you can do so as well.