This hack demonstrates the use of Yahoo! APIs to build a chat client which shows latest happenings around buddies and gives you the topics with which you can break the ice ;).
Yes, you can start a conversation with that out-of-touch-for-long girl, with something like, "Hey girl! Seems like its heavy rain near your place, you enjoying it ;)". Or may be, console your boss when the stock market has fallen down drastically, say, " Boss, you know what so-and-so stocks are gonna fall soon, better safegaurd your investment".