Google Wave is poised to potentially be the next big thing on the web. In a nutshell it combines email, chat, voice and documents into a single interface.
Unfortunately, it is not publicly available yet so there is a lot of a speculation on exactly what Google Wave does and how it works. If you are curious about it, here is a great Q&A session on Lifehacker which addresses common questions and shows several screenshots based on the authors experience.
Whether or not Google Wave will be a ‘[fill in the blank] killer’ remains to be seen. Personally, I do not really see myself needing or using the functionality it offers, but I am excited to see exactly what it is.

Jason Faulkner is the man who brings you our daily tips. He is based in Atlanta, Georgia.