/gib Project idea

Graphics tech demo including procedural terrain generation and post-processing effects, with A* path-finding.

Write a genetic algorithm.

Write a markov-chain IRC/IM bot.

Hanoi tower solver in 5 lines or less.

A 45 byte executable file (Yes, it's possible)

Random assembly challenges.

Memory management module, including a static 2-4mb buffer to 'allocate' out of, with a background thread acting as a memory de-fragmenting agent.

Project Euler.

Write bindings for a bunch of scripting languages such as Python and Lua to a game (new simple game, or existing game with SDK available)

Did he not say simple? /:

The tower of hanoi one is a good way of training logic, without consulting obviously..

They are pretty simple, and good practice

A game engine.

What is that?

Google, mai good friend.