Ever wanted your Raspberry Pi to talk to you? Adafruit has a guide for adding speech synthesis to a Pi so it can say all kinds of things.
In their example, they build a little talking clock, but you can do all sorts of things with it once you get the software installed. Being open sourced it's not likely to sound as great as off the shelf products, but it's still a fun little project that's sure to have some cool possibilities. Head over to Adafruit for the full guide.
Speech Synthesis on the Raspberry Pi [Adafruit]