For all you guys who can not put enough memory in their mobile gadgets aka notebooks e.g. for driving virtual machines and so on --> this is your time! 

Some examples (from 2011-11-18):

4GB DDR3 So-DIMM modules: starting from 10 EUR --> 8GB = 20 EUR

8GB DDR3 So-DIMM modules: starting from 78 EUR --> 16GB = 156 EUR

If you would like to push your device up to 16GB and you have only 2 slots available, make sure your technology is up to date. If you own a lenovo thinkpad, only the newest Intel i-core processors (sandy bridge) are working with the new 8GB modules.

At least these thinkpads are safe to use with 8GB modules: W520, T420(s), T520, X220, ...

By the way if you want to own now a new lenovo thinkpad by yourself have a closer look at the used (like new!) devices from NBWN.