At home -- set up your router with an uncommon password -- and set encryption using WAP2 -- as discussed above. It's a one-time thing and easy to do... so why not?
When on the road... I really don't worry about it:
o I've used public wifi -- some password protected and most without -- sending / receiving email, skyping, browsing, etc. without any problems. And no, all this time, my email has never been hacked nor do I receive more than maybe 1-2 spam mail a week (if that).
o I've used public PC's countless times around the world, including supposedly "dodgy places" like China and eastern Europe -- again without issues. This includes checking bank balances and buying plane tickets. I do make sure that I transact only on secure ("https") websites -- which is pretty much always the case with airlines, banks, hotels, etc.
No one can provide you with 100% security whether real world or virtual world. But the risk really is pretty minimal -- and some common sense precaution makes that even less of a problem.
If we believe all the hype in our media, none of us would be backpacking or traveling. Ditto for web 'dangers'.