Several manufacturers already offer CompactFlash-based 802.11b cards that can Wi-Fi-enable some PDAs and smart phones, but SanDisk is the first out with an SD (Secure Digital) Wi-Fi card. The SanDisk Connect Wi-Fi product was due in stores August 1. The unit lists for $129.

Eventually, many more PDAs and smart phones will come with slots for the postage-stamp-size SD format cards. For now, though, SanDisk is only supporting Pocket PC devices, and because the card only works in slots enabled for SDIO (SD Input/Output), an extension of the standard, there are only 14 devices that can use the SanDisk card.

SanDisk will add support for Palm OS 4.1 in October and Palm 5.x in November, the company says. It expect to see 25 to 30 SDIO-capable devices on the market by December.

The compatible Pocket PC devices: HP iPaq 3950/3955, 3970/3975, h2210/2200, h1920/1930/1940 PDAs, ViewSonic V37 and 36 PDAs, Samsung i700, i600 and M400 PDA phones, the NEC MIO PDA, NTT DoCoMo Sigmarion smart phone, JTEL smart phone, Dell X3 PDA and Mitac Mio 8210 and 339 PDAs.

Some of these have only just come to market or are scheduled for launch later this month or September, some may also not be available yet (or ever) in the U.S.

We used an iPaq 3950 to review an early production unit of the SanDisk SD Wi-Fi card. The first challenge was to upgrade the Pocket PC's firmware (from 1.0 to 1.11) to enable SDIO. This is a somewhat complex process that requires a decent knowledge of iPaq and Pocket PC basics.

Installing the SanDisk Wi-Fi card drivers from the CD provided was a simple process using the standard Microsoft ActiveSync software for synchronizing between a host PC and PDA.

Once both these processes were complete -- and after a "normal reset" of the PDA -- the Wi-Fi card worked right away on my home office WLAN, which uses a WGR614 Cable/DSL Wireless Router 54 Mbps/2.4 GHz from Netgear.