all of them work great... i bought an unbranded cheap card reader a long time back to use with my digi cam's sd card and it worked perfectly.
if u want to avoid the hassle of removing and inserting ur card everytime u want to add something to it then u can try out 'Softick Card Export II'
Link:
http://www.softick.com/cardexport2/
it's a software through which you can manage your sd card without taking it out of ur palm device. just run the application while in the cradle (or cable) and ur sd card shows up as a USB Mass Storage Device on the PC.