Alright JM2Hill!
You have several options before you. They are as follows:
1) Find a Jamis dealership and get the
Jamis Coda Comp ~ $775
www.jamisbikes.com/usa/thebikes/street/coda/12_codacomp_bk.html
This is a fast and versatile hybrid. It's good for commuting, exercise, sight-seeing, and running utility errands, once set up with rack. It can be equipped with fenders and up to size 38mm tires. It won Bicycling Magazine's Editor Choice Award for best hybrid of the year 2011.
2) Join a bicycle co-op and get assistance from the co-op with ordering the the sized bike from bikesdirect.com. The Schwinn Letour Legacy will give you many years of service. It's a 10 speed and has 105 components for the most part. I highly recommend it. After arrival, complete the build at the co-op. Ordering the correct size the first time around is crucial.
The Schwinn Letour Legacy ~ $800
www.bikesdirect.com/products/schwinn/schwinn_letour_legacy_xi.htm
This is just a very fast and reliable bike!
*This is the best bang for your buck!- If the sizing is correct...
3) Go to a Marin dealership and get the
Marin Muirwoods ~ $630
www.marinbikes.com/2012/bike_specs.php?serialnumb=2207&muirwoods
At 5' 6", this bike will most probably suit your fancy because it will give you a greater sense of control and confidence, due to its lower profile (size 26" wheels) and its wider tires. It's built like a tank! If speed is not a major factor, but comfort, dependability, and durability are your primary points of focus, then this is your bike. It's an urban stealth bomber! This is a fun and get-outta-my-way kinda bike! Gangwaaaaay..............
* It ain't that slow neither!
4) Since you have no serious hills to speak of, you really don't need a multi-geared bike! A single speed can provide all of your cycling needs. Single speeds are efficient, low maintenance, and inexpensive in most cases.
I would recommend the following single speeds:
a) The KHS Urban Soul ~ $400
www.khsbicycles.com/06_urban_soul_12.htm
b) The Schwinn Madison ~ $585
www.schwinnbikes.com/bikes/urban/2012-madison-14401/
c) The Felt Brougham ~ $550
www.feltbicycles.com/USA/2012/Fixie/Fixie-Series/Brougham.aspx
d) The Trek Earl ~ $530
www.trekbikes.com/us/en/bikes/town/urban_utility/earl/earl/
e) The Raleigh Back Alley ~ $550
www.raleighusa.com/bikes/steel-road/back-alley-12/
Good Luck!
PS.
You're only traveling about six miles per day round trip. That's a short trek!
Perfect for hybrid or single speed cycling.