Messaging
Messaging features on the K1 are standard, if pretty comprehensive. The phone supports SMS, MMS, and Email but not IM. Messages can be stored to a SIM card and also transferred via Bluetooth to compatible computers and printers.
The built-in Email client supports POP3 and IMAP4 protocols, and while the low-resolution screen doesn't make for easy scrolling through loaded Inboxes or lengthy messages, the client works simply and effectively. Motorola's enhanced predictive text input system works quite well (though pressing the right directional key can be tricky if you have big thumbs) and practiced mobile messengers should have no problems using the K1 to write acronym-laden SMSs with one hand. "KRZR" and "K1" are, of course, already in the phone's dictionary.
While a smartphone would be the mobile communicator of choice for the businessperson who needs "always-on connectivity," the KRZR's messaging and Email capabilities are better suited to someone who occasionally needs to field a few messages on the go, but is happy to wait until returning to a PC to fully manage his Inbox.
Internet
Similar to its messaging capabilities, the K1 is a functional but not spectacular Internet client. While Verizon is selling their K1m with VCast broadband service support installed, the unbranded GSM K1 features a standard WAP browser that I easily configured to work with T-Mobile's TZones service.
The K1 did well with basic WAP websites as well as navigating the largely text-based TZones site. Again, simple information retrieval works well on the K1's smallish screen and standard keypad. If you need to look up the occasional movie time, restaurant address, or sports score, the KRZR will do you just fine. Extreme users in search of full HTML browsing, on the other hand, should perhaps look elsewhere in Motorola's lineup - say in the direction of the Linux-based MING A1200.
Connectivity
Motorola built the GSM K1 with support for class 12 EDGE high-speed cellular data transfer. The phone also features a single mini-USB port for file transfers and syncing with a PC via an optional data cable.
Bluetooth includes support for mono and stereo audio devices as well as file transfer and syncing with other devices. I had no trouble pairing the K1 with a mono headset or my computer, though I did not have access to a stereo Bluetooth headset for this reveiw. Note that the Alltel and Verizon-branded K1m models have limited Bluetooth support - as of my writing this, Verizon was supporting headset and image transfer, but not full file transfer (i.e. You can't install your own ringtones via Bluetooth).
The K1 also has a microSD removable memory card slot tucked in behind the back panel and literally on top of the SIM card slot. No microSD card shipped with my K1, but the phone recognized a 1GB card I installed in it, and was able to read music and image files I'd transferred from my computer.
Next: Conclusion » 
4.7
