I read about the VDIP2 online, then by chance, my latest read "Practical Arduino" had a project which used the VDIP1 module. Since I'd like to have configuration separate from logging and the VDIP2 has 2 USB ports and was only a few dollars more, I thought "why not?!"
The same project was also automotive based and had a power supply design that used a different voltage regulator than I am accustomed to using. It is a "low drop out" model (LM2940CT-5.0) that can handle the low voltage conditions during cranking. The power supply design also deals with overvoltage and provides a capacitor that acts like a battery to allow shut-down time in the event of total loss of power. Very cool and highly PRACTICAL. I've ordered the voltage regulator and some other parts necessary to make the power supply (oops, just remembered that I forgot to order the cap...) for when I get to automotive use - that will be some time, but good to know there is a design ready. I included the I2C buffer chips and some sockets in the order. I'm thinking that they can't hurt, so why not have them on hand if needed.