As I find terminals in the marketplace that meet current security standards as of April 2007 I will post them here for handy reference. All new models introduced have encryption chips, an essential key to meeting security requirements.
Nurit 8000 portable wireless payment terminal
Omni 3700 family
Verifone Vx 510 portable wireless payment terminal
Verifone Vx 570
Verifone Vx 610 portable wireless payment terminal
Verifone Vx 670
*Verifone SC 450 handheld PINpad
*Verifone SC 455 handheld PINpad (essentially same unit as above, but with graphic display)
Verifone SC 550 handheld PINpad same features as 450, 455 but with dual card reader
Verifone SC 552 same features as 550 but it adds a 2nd smart card reader/writer which can be used as a removable encryption module
Xplorer portable wireless payment terminal (Verifone)
* may be manufactured without the security chip for applications where smart card-only support is required.
UPDATE- THE LIST ABOVE IS OUT OF DATE- DO NOT USE.
The PCI security standards Council maintains a list of approved pin entry devices.
See related article, is my Nurit 8000 PCI compliant?