WEP passwords can be bruteforced in a reasonable amount of time... but you don't even have to do that to gain access, afaik... Something about packet injection that I haven't bothered to look into.
Yes, f0dder, that's one of the main reasons i made this thread, to have an idea of the real dangers of having such network.
But the thing is: you have to do some digging to crack a wep network (i've made some without success). Another thing is that my router is quite bad, it doesn't even cover my house deccently, which means that it doesn't cover anything more than my neighbours' appartments. And i know every of my neighbours, and they're all old people that i don't think even have a computer at home
So, i feel quite secure, i just keep the password on the router for safe-keeping.