To take advantage of ReadyBoost, you need at least 1GB of free memory on a flash drive,
and ReadyBoost can take advantage of up to 4GB. That's why, if you're running Windows Vista,
it's a good idea to use higher-capacity flash drives - so you'll have plenty of memory for ReadyBoost,
and plenty for your file storage.

Ref: http://www.sandisk.com/Retail/Default.aspx?CatID=1472

I tried using my 512Mb Kingston DataTraveller USB2.0 flash drive for the
Speedboost feature, but the OS responded say something to the effect of 'you
drive isn't fast enough/good enough' for this prupose.

I'm surprised at this. Is there any indication anywhere of what is required
of a usb drive to be suitable for SpeedBoost?

Here is more than you ever wanted to know about ReadBoost!
================================================
From Tom Archers blog on ReadyBoost msg by Sefi on Sept 12, 2006
http://blogs.msdn.com/tomarcher/archive/2006/06/02/615199.aspx

In some cases even a slower USB device could help. For example an older
notebook
with 1G ram and a slow HDD (4200RPM). It these cases you can enable
readyboost
with a slow device.

1. Let Vista test is, and check the Do not Retest this device checkbox.
2. Unplug the device
3. Go to regedit
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\EMDMgmt
4.find the key related to you device (the device  vendor and name is in the
key)
5. Change the follwing values:
Device Status 0x02
ReadSpeedKBs 0x1000
WriteSpeedKBs 0x1000
6. Plug the device, right click on it to open properties and enable cache.
------------------------------
A list of devices
http://www.grantgibson.co.uk/misc/readyboost/
------------------------------
A recent review of devices and list of those that worked
http://www.activewin.com/reviews/hardware/memory/vista/readyboost.shtml
ReadyBoost compatible devices must have do 2.5MB/sec throughput for 4K
random reads and 1.75MB/sec throughput for 512K random writes, if they don’t
they won’t qualify.

·         Apacer Handy Steno       2GB
·         SanDisk Cruzer Mini        256MB
·         Kingston DataTraveler ELITE
·         Crucial Gizmo!Overdrive
·         SanDisk Cruzer Micro (U3)    2GB
·         Sony MicroVault               512MB
·         Lexar Secure      1GB
·         SanDisk Cruzer mini        256MB
·         SanDisk Cruzer Micro     1GB
·         Crucial Gizmo     256MB
·         SanDisk Cruzer Mini        1GB
·         Apacer HT203    1GB
·         ATP Petito           1GB
·         Sony MicroVault               256MB
·         Kingston Data Traveler 1               1GB
·         Sony MicroVault Tiny     2GB
·         Patriot Xporter XT            4GB
·         SanDisk Ultra II CompactFlash    2GB
Best for Price: Apacer Handy Steno HT2003
Best for Price against Performance: Apacer Handy Steno HT2003
Best overall performance: Apacer Handy Steno HT2003

CJM,

Possibly what I'm sharing has previously been shared but I don't think so:
There are three (actually four) types of Flash Media 1) Fast Flash 2) Slow
Flash 3) Fast and Slow Flash combination. And then there is a type of Flash
that is factually a HDD.

An appropriate 4 Gig Fast Flash will provide Vista with an increase of 1.5
Gig RAM.

FYI: My new 2Gb Kingston drive was slotted in and tested and *is* suitable
for ReadyBoost.

I'm not sure about performance yet - it's hard to tell. Can anyone thing of
a With ReadyBoost/Without ReadyBoost test to measure the performance gain if
any?