use other high speed Flash memory for memory boost?

Sure.

I think you will find they are not fast enough. If you have a usb 2.0 card-reader and either of those, give it a try. I have both CF and SD by sandisk (Extreme III) and neither are anywhere near quick enough. Just don't go out and buy one for ReadyBoost - you'll be wasting your money. There are too many cheaper devices that work great with RB.

In any event, give it a shot. You can force Vista to use one by selecting the appropriate drive's 'properties' and telling it to use that device. After RB has tested it, it may be deselected by Vista. That 'feature' makes some people think RB is broken, especially with the Sandisk Cruizer parts; RB will initially accept them and then later reject 'em because they are just a little slower than what is required (regardless of what others may tell you). On April 5, Sandisk released the 'Cruizer Contour' in 4 & 8G and those are the _only_ ones Sandisk claims will work with RB.

After the built-in RB performance tests, you can search your registry for ReadSpeedKBs and WriteSpeedKBs. Those numbers need to be greater than 3500 and 2500 respectively, before your device is really usable by RB.

Good luck

It sounds like you may be a registry newbie so here's the long-winded version... open the 'start orb' and in the search field type in 'regedit' and then just press enter. It will ask you if you approve (admin approval) - once it comes up and is running do edit->find (^F) and enter 'ReadSpeedKBs' in the search box and just sit back and wait. If you have ever installed a USB drive in your computer, it will find the value. if the ReadyBoost test has been run on this drive it will have a non-zero value. A couple of fields down from there will be the 'WriteSpeedKBs'. If you press 'F3', regedit will move to the next one, if there is one.

Just a warning - if you haven't messed with regedit before, don't change anything (ask first). In regedit, when you change it, it happen 'right now', you don't get to change your mind and there isn't an 'undo'. It wouldn't hurt to do a restore point and/or back-up your registry (unless you feel brave today).

There will be an entry that you are searching for (ReadSpeedKBs), for every USB drive you have ever installed and there may be multiple keys for the same drive (the registry is really a stupid file - but that's ok, it knows you are smart!). There will be entries for any size or type of USB drive you have ever installed. It is up to you to find THE one you are looking for. I usually give my drives a name when I format them because it helps to locate it later.

This is an example of the key-name for my ReadyBoost drive. Yours will be the same, all the way to (and including) EMDMgmt after that is it drive specific. The next value is my flash-drive key (note, the volume name is BADASS). The stuff on the right side of the screen are the values you are actually looking for.

good luck.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\EMDMgmt\_??_USBSTOR#Disk&Ven_USB_2.0&Prod_Flash_Disk&Rev_1100#AA00000000000131&0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}BADASS_2226904866

This is a 4G A-Data drive
ReadSpeedKBs is 5403 (minimum 3500)
WriteSpeedKBs is 8852 (minimum 2500)