SMC has thrown the kitchen sink into its traveler's access point, a street price $99 device that has the full complement of Wi-Fi options: The AirPort Express ($129) from Apple may be cute and small, but the SMC has four modes versus AirPort Express's 2 1/2. Express can act as a client (for streaming music and USB only), a WDS relay or remote (to Apple or compatible gateways only), or a standalone 802.11g/WPA gateway. I count Apple's client mode as 1/2 since it can't handle traffic over its Ethernet port as a bridge in that mode, apparently.
The SMC--trippingly off the tongue call it EZ Connect™ g 2.4GHz 802.11g Wireless Traveler’s Kit (SMCWTK-G)--can act as an access point, an Ethernet bridge (so full MAC masquerading onto any network), Ethernet bridge, repeater, and point-to-point or point-to-multipoint bridge. (Those last two are similar WDS modes, so I won't count them separately.)
SMC doesn't mention weight or the size of the power cord. The Express has an integral power plug, but you can get an extension cord as part of an audio/power kit for $39. The SMC unit can draw power over USB, too. [link via Tom's Networking]