The QWERTY keyboard dominates text input in computers: a deplorable and pathetic case of technological inertia which can be greatly improved with minimal modification.
The QWERTY key layout (key map) is distinctly awkward and deficient in many ways. The Dvorak key map is better, but it also has problems.
Colemak is similar to QWERTY (i.e. keys for many common shortcuts remain in the same location), yet it is also more efficient than Dvorak. You can compare them with your own prose.
If one is adept with QWERTY, then learning a new layout may be initially frustrating. In any case, I found Colemak to be a worthwhile improvement even without touch typing. Essentially, any layout which maps the most frequently used characters to the home row provides similar advantage; i.e. less hunting, more pecking. For minimal disruption, try QWERTY-Flip.
Common computer keyboards have asymmetrically staggered rows, mimicking the mechanical typewriters1 they replaced, but the ghosts of implementation constraints continue to haunt us, and (in ill irony) even many so-called «ergonomic» keyboards persist with this staggering arrangement. In contrast, here are some honestly ergonomic keyboards:
I must say, the Blickensderfer is one typewriter that wins my respect. ↩