This is an excellent solution for you PSP.
Order a Sandisk Micro SD 6GB, 17.99,then a Micro SD to Memory Stick Pro Duo adaptor, 2.99. Order both at once and you only pay postage for 2.99. All together you pay 24.93 and you get a 6GB memory stick pro duo.
Note that on their website they said this adaptor is not compatible with SDHC, but I tried this afternoon, the 6GB micro sdhc card works great with the adaptor! the speed to read and write files is even faster than those fake memory stick pro duo. The 6GB Micro SD card comes with an SD adaptor and a USB adaptor, which is very worthy.
Follow the steps below:
1.go to mymemory.co.uk, search sandisk 6GB, click and add into cart.
2. Search "duo adaptor", add the product "MyMemory MicroSD / MS Pro Duo Adaptor" into cart.
3. check out. it will cost 24.93 and you get a 6GB memory stick pro duo!
Hope you all enjoy.