If your iPhone is compromised, you also lose the passwords to log into your Gmail or whatever provider. WEP/WPA keys are the least of your worries.

One possible workaround for typing in huge WPA keys is to use Apple's iPhone Configuration Utility. You could create a profile for your local network, including all the key bits, and just email it to yourself. The mail client, when it sees those config files as attachments, does the right thing when you click on it, including a nasty warning message. (That's how our IT people set up my iPhone to use our 802.1x system.)