Synchrotech has released its "MicroU2E USB 2.0 to USB 2.0 Mode Express Card", which is yet another way to integrate an ExpressCard into a machine that wasn't originally made to accept them. Of course, other methods of getting your ExpressCard to function via USB do exist, but the MicroU2E is a simple and small device that works solely with USB-based cards and provides all the power it should need for that HSDPA / HSUPA card to function. It does not support any PCIe based ExpressCards. It's expected to retail at $40 and it works with both Vista and OS X.
Source: Synchrotech