A few exceptions: Lenovo's ThinkPad Tablet and Asus's Eee Pad Transformer TF101 and Eee Pad Transformer Prime all offer a keyboard and cursor control in a case that uses the USB port or dock.
The $69 Apple Wireless Keyboard and Logitech's $70 Bluetooth Tablet Keyboard for iPad 2 and for Android (3.0+) are decent units that won't weigh you down too much. Logitech also makes a $130 folding keyboard that travels a little more compactly, and the company's $100 keyboard/case for the Samsung Galaxy (10.1 inches) is another workable solution. With Windows 7, a portable mouse is a good and necessary accessory. Navigating its non-finger-optimized interface is difficult at best without it or a stylus. Any of a host of USB (including wireless) and Bluetooth mice that work on laptops and desktops will work just fine on a Windows 7 tablet.
Most tablets, like the iPad, have a capacitive touchscreen, which senses input from conductive materials, such as a living finger. These will work only with your finger, or a chunky capacitive stylus. But for serious drawing or for taking handwritten notes, you'll need a special pen-and-tablet combination.
Many of the business-focused Android and Windows slates come with active digitizer technology -- which requires an electronic pen -- in addition to the capacitive touchscreen. An active digitizer lets you lay your hand on the screen without interfering with the pen's input, and increases accuracy and pressure sensitivity.
N-Trig-based tablets are great for those who do a lot of handwriting or a little drawing. N-Trig’s Duo Sense dual pen and touch-active digitizers are found in Android tablets with N-Trig’s digitizer, such as the HTC Flyer and Jetstream and the Lenovo ThinkPad Tablet. N-Trig-based Windows slates include the Fujitsu Q550, both the HP Slate 500 and the newer Slate 2, and the Motion CL900.
Each of the Android tablets comes with special note-taking software, such as Notes on the HTC tablets, and My Script Notes Mobile on the ThinkPad. However, if you want to do more drawing, you’ll want to check out Wacom-based Windows slates like the Asus EP121 or the Samsung Series 7. Wacom pens will not work on N-Trig tablets, and vice-versa.
Connectivity and PortsWi-Fi: All tablets have Wi-Fi. However, not all have 802.11a, the 5GHz band traditionally used by businesses. 5GHz is also used in newer dual-band consumer-grade routers and can result in a better connection, simply because there are fewer devices using it.
The iPad 2 supports 802.11a, as does the Samsung Galaxy Tab 10.1, but many others do not. This is a feature some business users might need to connect in their offices.
Broadband: An increasing number of tablets have wireless broadband. Some iPad 2 models provide 3G broadband connectivity to either AT&T or Verizon and on a month-to-month basis -- no service agreement. Samsung's 4G Galaxy Tabs, Motorola's 4G LTE Droid XyBoards, and others sold by providers also offer broadband, but these models are on a two-year contract basis. Given the fast pace of change in tablets today, a two-year contract could be too long a commitment for a small business.
If you're buying a tablet with mobile broadband, we suggest sticking with one that has 4G, so you can get the maximum possible speeds. At this writing, you're limited to 3G on an iPad 2.
Ultimately, whether you'll need broadband is something only you can decide, but either way, expect the broadband-enabled tablet to cost more than the baseline model. It might be more flexible for your business to use a mobile hotspot such as Samsung's LTE router, instead.
Bluetooth: You probably want Bluetooth if you have any intention of using a portable keyboard and mouse with your tablet. For connecting peripherals, 2.1 is fine. Few tablets lack Bluetooth, with the exception of some value-priced, consumer-centric models such as Amazon's Kindle Fire and Barnes & Noble's Nook Tablet.
USB: Whether you need USB depends on how you want to store and transfer files, and whether you want to leverage USB peripherals (such as a mouse, gaming pad, or keyboard). Apple's iPad lacks any integrated ports, though you can add one that will communicate with digital cameras for $30. Only a handful of Android tablets, including the Lenovo ThinkPad Tablet, the Acer Iconia A500, and the Toshiba Thrive, have full-size USB ports that will power an external drive. More common are micro-USB and mini-USB ports that won't.