I am getting my new Treo 650 (Sprint) on Tuesday and am looking for the MUST HAVE software to help for business. I am basically going to be a "mobile office" and will have have my laptop with me as well as my phone. What are you guys using on your Treo's that help with your business?

P.S. I am in work for a major home builder in land acquisition (if it helps).

P.S.S. One thing I am going to need is efax (or similar). Any thoughts or suggestions?