Thanks again to everyone who shared their methods for running the Pi through the laptop.
My goal was to run the Pi through the laptop without a router in between, and have the Pi share the laptop's wifi when the laptop has internet access.
Here's the method that ended up working best for me:
- ethernet cable between laptop and pi
- ethernet address set to static on both sides
- wifi address set to dynamic on both sides
- On the laptop use the bridging feature to bridge the ethernet and wifi.
- Use WinSCP for file transfer between the two.
I also tried the adafruit cable mentioned by dirtbikerxz. I actually had the cable but didn't realize what it was for. The cable ended up being a little quirky - the driver didn't work, and I had to download this alternate driver
http://www.ifamilysoftware.com/news37.html, and the driver executable has to be run every time the cable is used. Also, when using the serial cable the putty window had some issues with command lines wrapping around.