It's very interesting to think about cases in which "progress" causes people to abandon a technology before it's perfected. For instance, with the advent of fuel-powered ships, sailing ships became outdated, which meant that there was no longer a compelling economic reason for people to continue improving the technology.
Now, as a fascinating and inspiring post over at Alternative Energy Blog explains, people are taking a new look at sails, and figuring out how to make them more efficient:
Modern windships can...take advantage of new technologies and materials that weren't available in the days of sail. Wind tunnel tests on different types of rigging and sails quickly showed the Danish team how poorly traditional sails perform....So the Danish team came up with an alternative that exploits materials borrowed from the aerospace industry. Using high-performance steel for the masts does away with the need for stays to hold them upright. The sail itself is made of fibreglass, with a profile like an aircraft wing. Flaps on the sail's trailing edge generate extra thrust when extended, but can be retracted to minimise aerodynamic drag - important when using engine power alone. Wind-tunnel tests showed this design to be twice as efficient as the sails on a traditional windjammer.Even more promising is the SkySail, a sort of giant kite which harnesses the stronger and more reliable winds that prevail about 1500 feet above the ocean:
SkySail's largest version, with an area of 2000 to 5000 square metres, will generate propulsive power equivalent to a large ship's engine....One wonders how many other common technologies from past centuries could be improved, given the knowledge we've gained in the interim. (I can't help daydreaming about possible applications for oversized wind-up motors and clockwork.)
AEB goes on to describe solar ferries, gravity-powered planes, and other remarkable things. Be sure to check out the links at the end!