URL shorteners usually assign you a "path" (the final segment of a URL other than any parameters) that is either a hash or a custom string of your own choosing. Hashes are hard to remember and custom strings aren't usually very short (the short ones tend to get taken early).
Instead, I found a way to produce paths that are always short but still easy to remember because they draw on natural language. Can you guess how?
The solution is described in this lightning talk I gave at Hack and Tell last night. The proof-of-concept is in this GitHub repository.
I guess I'd better supply the expected short URL for the slides, too: https://t.co/yNpQiCNMhe. Find it easy to remember?