In the olden days, when your desktop PC got too old, it was either upgraded or cannibalised. They never really hung around. But in this era of laptop domination, when a computer outlives its usefulness, you can just palm it off!
Your little brother, your college-bound sister, your grandparents who just want to talk to you on the internets, they'll all be grateful for your crummy old laptop. Especially when it lets you get away with giving them Christmas presents like these.