Hardware accessories add functionality and help personalize Windows Mobile devices. Many independent vendors offer Pocket PC and Smartphone accessories, but the first place you might look is the Web site of the manufacturer or vendor of your particular Windows Mobile device. They will have replacements for accessories that shipped with the device, and add-ons that they support and certify to work with the device. Note that some manufacturers also sell their Pocket PCs, Smartphones, and accessories through independent online vendors, such as MobilePlanet (http://www.mobileplanet.com).
Asus
The Asus Web site (http://www.asus.com/products/pda/accessories.htm?kp=pda) describes all of the accessories they have available for their Pocket PC. To purchase them, you have to go to an Asus reseller. A list of online resellers is found on this Asus Web page (http://usa.asus.com/wheretobuy/WTB_PPC.htm).

Thumb keyboard for the Siemens SX56 Phone Edition device marketed by AT&T Wireless.
AT&T Wireless
AT&T Wireless markets and supports Pocket PC Phone Editions and Smartphones from Audiovox, Motorola, and Siemens. You can find and purchase accessories for these devices online. Start at this Web page (http://www.buywirelessnow.com/attwireless/PhoneList.asp).
Audiovox
Audiovox offers some accessories through the Web. Go to their Web site (http://www.audiovox.com) and follow the “Shop Online” link to their Online Store. In addition, Audiovox Pocket PCs and their accessories are sold through wireless service providers like SprintPCS (below) and AT&T Wireless (above).
Dell
Dell sells accessories for its existing and discontinued Pocket PCs on its Web site. Go to this page
(http://www.dell.com) and click on the appropriate accessory link on the left side of the page.
E-TEN
E-TEN describes the accessories available for its P300, P300B, and P700 Pocket PCs on its Web site. Go to this Web page (http://www.etencorp.com/products.html), click on the link to your Pocket PC model, and then on the “Accessories” link. In the U.S. you can purchase E-TEN Pocket PCs and accessories from Convergent Technology (http://www.convergentech.com).
Hewlett-Packard iPAQ
HP offers accessories for its iPAQ line of Pocket PCs through its resellers and from its online store. In the U.S., go to this Web page (http://www.shopping.hp.com), follow the link to “Handheld Devices,” and then to “iPAQ accessories.”
Hitachi
Hitachi offers its G1000 Phone Edition in the U.S. through SprintPCS (see below)
I-Mate
I-Mate markets Smartphones and a Phone Edition, and their accessories. Go to the Club I-Mate Web page (http://www.clubimate.com/), click on the “Shop” and select “Accessories” from the drop-down menu.
MiTAC
MiTAC sells it Mio DigiWalker Pocket PCs and their accessories though a number of vendors in the U.S. A list of them is available on this Web page (http://www.miogps.com/where2buy.htm).
Motorola