I have found that responses generally fall along a spectrum of feelings that range from fear to hostility. The feelings of fear might originate from a misunderstanding of what the disorder really is and being afraid of the mania which causes a person to act out of control or of the depression and the possible that their loved one might commit suicide. The hostility on the other hand can be a denial of the realities of the dangers their loved one faces. However, there is also the love, support and understanding that you may get from other people so it is important not to let the bad take over.
Personally I think I have encountered just about every emotion across the spectrum. My parents are extremely supportive but I think deep down also a little scared. I live pretty far from them so they don't have the opportunity to see me on a regular basis. Since I was diagnosed I have only seen them a hand full of times. I plan to move home shortly and I think they are a little afraid of what to expect. They say that they have noticed a difference in my personality since I have been on medication and it is for the better.
My close friends who know about the disorder have been the most helpful. When I feel like I am having an "episode" I am able to talk with them about the way I am feeling and it is a tremendous help. They can't replace my doctors but because they know me so well it is easy for them to remind me of the good times when I am feeling overwhelmed with depression and to talk me down when I feel out of control. They have no judgement and always treat me with respect.
On the negative end of the spectrum would be one of my roommates who uses my disorder as a way to be a jerk. He is not the best roommate by far and when it comes time to address his not so great roommate behavior he often finds it necessary to say with disgust "what are you off your meds today". It makes me feel like less of a person because of my disorder and goes right to the heart of my fear about being labeled as a person who is "on" medication. But I have come to learn that he is only one person and no matter what he thinks or feels I have way more people in my life who support me than don't.
What I have yet to negotiate is how I will deal with my disorder in the working arena. For each individual with this disorder it will be a personal decision. Some people choose never to tell their employer that they are bipolar while some people choose to be upfront about it just in case they have an episode that might affect their work performance.
Regardless of what other people think the most important thing is how you think of yourself. As I have said before being bipolar does not mean that you are crazy and really is there such a thing as being normal? Just think about it.