In the US, case law supports GP's argument: http://en.wikipedia.org/wiki/Feist_v._Rural

The key bit, is if it's published and a fact or collection of facts it can be reused.

It's more likely a Tu-143 with a larger wingspan and upgraded guts. So more like 70s or early 80s technology.

Something simple like a basic Webserver (GET/PUT/HEAD) or a FTP server.

You get:

a) simple string parsing/processing/manipulation
b) File I/O and filesystem manipulation
c) Network I/O

Optionally or language dependent:

d) Threading
e) Packaging

If a dynamic language (e.g. lisp):

f) Write something like JSP on top of it: dynamic dispatch to handling method/function

Optimizations are easy as well. Caching will give you a good overview of data structure speed.