Well it looks like there's a nationwide outage of Blackberry service at the moment. Some people can send, but most people cannot receive messages.
*Note* Guess I should have looked closer at the source that I just posted and saw that the date of that linked article was 1 Dec 2004.
Might have something to do with their rollout of the version 4 software? Too many people downloading it at once, perhaps? At any rate...not good considering we just rolled ours out.