Preamble:So, a couple of months ago the USB cable which came with my Nexus-S stopped working for data transfer. Since then the number of pictures and videos has been steadily building up. Today I decided to solve that by getting a wifi link to my phone working.
I tried a number of free apps, but none of them could transfer more than one file at once. Then I stumbled upon Software Data Cable, so I thought I would share.
1) Find and install the free 'Software Data Cable' app on your android phone.
2) Launch it and click on 'Start Service'
3) Download a FTP client on your computer if you don't already have one. I use the free FileZilla client
4) Launch FileZilla
5) On your android there will be an address which looks like ftp://192.168.1.3:8888/
6) Type the 192.168.1.3 bit into 'Host' and the 8888 bit into 'Port'
7) Click QuickConnect
Now you can drag and drop files and folders from you phone (on the right) to your computer (one the left) or vice versa.
Speed up Transfers:
In order speed up the transfer of lots of files do the following:
i) In FileZilla click on 'Edit' -> 'Settings'
ii) Click on 'Transfers' in the left pane
iii) Change 'Maximum simultaneous transfers' to 1
For me this approximately tripled the transfer speed.