A neat compromise is a case such as the Belkin YourType Folio and Keyboard, which has a removable keyboard. This design allows you to carry your iPad in just the slim protective folio, adding the bulk of the keyboard to the case when the situation demands it.

How much bulk are you willing to deal with? You can't avoid picking up some extra bulk when you strap a keyboard onto your iPad, but some cases are slimmer than others. Of course, what you give up in added bulk, you gain in added protection.

If you don't mind leaving the iPad's back exposed, check out the Logitech Ultrathin Keyboard Cover or the Logitech Keyboard Case by ZAGG. For a case with the flexibility of a slim folio plus a removable keyboard, check out the Belkin YourType or the ZAGGfolio. If you need more protection and don't mind extra bulk, take a look at the Kensington KeyFolio or the ClamCase.

For complete details, see the full reviews of all the keyboard cases I tested: