I came across this deal earlier this week and it was shipped to me so fast that I am able to confirm this for you in time for you to take advantage if your so inclined.
Fry’s is selling 8GB Lexar Platinum II Memory Stick PRO Duo (PSP Compatible) here on their website for $49.99 including free shipping. After this $37 rebate you end up spending about $12. Its a great deal if you dont mind waiting a month or two for the $37 rebate. 8Gb memory sticks for the PSP typically run anywhere from $50 (if your very lucky) to over $120. So getting one for $12 is a STEAL. You only have until this Saturday to take advantage of the deal so act fast. To qualify you must purchase by Saturday, October 30th. You then have 30 days to send in the rebate form.
I tested the Lexar Platinum II Memory Stick PRO Duo card I received from this deal yesterday on a PSP Slim with custom firmware and it works fine. ISO, CSO, and all other file types play fine. Games run perfectly. I noticed no difference in loading times from my Official Sony Memory Stick. These Lexar memory sticks are Magic Gate supported and the platinum series has a lifetime warranty.