I'm new to the commuting thing - this is my third year, but I would consider my commute a technical challange for me. I'm on a Trek hybrid. I live/work in an urban/suburban area, and my 20 miles round trip commute ascends 213 feet. When planning my route, I have to take into consideration getting across two rivers and two major highways (which don't allow bicycle traffic). I live in the most densely populated county in the most densely populated state, and yet, I'm managed to find joy in the many VC challenges that I face during my ride. I start out on a long and steep hill, hit the bike path through the park and head over the first bridge. All of my intersection turns on the commute in to work are left turns, so I've gotten very accostomed to merging left and turning at lights, which was scary in the beginning.
After the bridge, I have to go through a very hilly city with truck traffic, narrow roads, no shoulders and street parking. I usually take the lane and ride with traffic and try to make eye contact with drivers to let them know what I'm going to do. I haven't had any problems with the drivers behind me, mostly I worry about the drivers running stop signs on the cross streets. Taking the middle of the lane helps a great deal in this regard, because the other drivers can more easily see you coming, and I then have more time to react in case they don't. After I leave the city, I end up on a 45MPH road with two hard merges coming from my right. I try to slow down and merge across the off-ramp to the right, but sometimes the drivers get confused when they see me coming up on their left and either speed up or slow down. This is when eye contact and definitive hand signals help to clarify the situation. A mile or two up and down this hilly highway and I have to merge left two lanes to make a left into a suburban development. I have the common issue of not setting off the light sensors, so if I'm unlucky enough not to have a car behind me, I have to pedestrian cross or else wait until a car pulls up. Once in suburbia, I can relax a bit and enjoy the scenery. A couple more lights, and a harrowing municipal street with terrible potholes and debris and I end up on the one stretch of road that gives me the most trouble. It's 40 MPH and no shoulder. I stay as far right 'as practicable', but with traffic as it is in the morning, grumpy drivers don't like having to merge left for me. I've gotten yelled at, honked at and almost hit here several times. I've actually changed this part of my route last week, and added two extra suburban miles to avoid this short stretch of road.
At the end of my route, I cross a large mall parking lot which has fantastic roads and no traffic in the morning, and pull up at the door of my office across the street, reading for anything!
We have a few bike paths where I live, but no bike lanes, and many roads without even sidewalks or shoulders, so I have no choice by to ride vehicularly. I find it safe as long as my actions are predictable, and I can negotiate with drivers. I handle the angry driver issue by making eye contact whenever possible, smiling and waving when drivers do the right thing, even if they are supposed to - I want drivers to have a good experience with me as a bicycle commuter so that they treat other cyclists with respect. I try to avoid being confrontational as much as possible, but I don't hesitate to yell out if someone is compromising my safety.
I wear a flourescent yellow jersey and have blinkers for going under bridges and overpasses. I don't ride at night, and usually only in good weather, so I haven't invested in a reflector vest. When in doubt, I slow down and think about how to negotiate traffic. I don't run stop signs or red lights, even if I'm the only person there. I think that I get more respect from drivers when they see that I don't take short cuts. There are times that I must do a pedestrian crossing, and I always walk my bike across the cross-walk. If I lived in a more rural environment, I might be a little less stringent, but there are too many people are cars where I am to chance it.
As far as other uses for the bicycle, I do enjoy grocery shopping and running errands, though I can't say I've made the jump to hard-core year round riding. Hopefully, as I gain more experience I can continue to reduce my dependance on a car.