lol- you are barmy! letterletterletter.com is so funny- can't see it getting a huge influx of type-in traffic but it does have a use, maybe even for someone like me! I have 3characterdomain.com and I would buy your domain to partner it if you didn't want much for it (pm me)
My appraisal for that is $20 to an end user- i.e. me! haha
As for the other domain- can't really see it myself, but if you want the postcode so you can carry on doing what you're doing I believe its 20500!
You could get an info site on there I guess, you could probably sell it to G. W. Bush himself, he seems to do crazy things other people tell him to every day of the week. Just tell him its definitely worth 5brazilian dollars...