Lets cover an area of working the room with which people often struggle... the actual moving around the room. Disengaging with one group and breaking into groups. Finally I will cover the bridge process and explain the importance of the follow up after we have met new people.
Perhaps you have recently had a chance to meet people at a business networking event or social event, a conference, or seminar and have taken the opportunity to go up to someone standing alone. The problem comes when you wish to extricate yourself from this person but don't know how to go about it. Here let me give you some practical ideas. If you are both fellow guests at a function you don't owe it to this person to spend the rest of the evening with them. Think about it for a moment, the chances are that this person wishes to move on as much as you do but like you they simply don't wish to offend or cause any embarrassment.
You can do one of three of things:

After you have finished speaking you can simply say Well, Jo, its been great meeting you, enjoy the rest of the evening. Please excuse me as I promised to go and talk to Gerry over there
You could say, Im going to get another drink, would you like to come?
The cowards way out is Please excuse me, I need to go to the loo! and make sure you move well away from the person.

Whichever you use please do it with respect, integrity and politeness. Good manners is essential when working the room and is good business; bad manners brings no business.
The important aspect here is to move around the room with or without your new found friend. Again can I remind you that if your conversation is dry, they too probably want to be off working the room as well. You are doing them a favour by using your superior business networking techniques

Using the second idea of moving to the bar is an opportunity to park the person with someone else or for them to park you. Its rare both of you will be at an event where you don't know anyone so moving to the bar usually has the desired effect. When you do bump into someone you know even though you are a guest at an event act as a host. Dont just say Hi Lou this is Jo and leave it there. You have been chatting to Jo for some time and you obviously know Lou so play host. Say something like this, Lou let me introduce you to Jo who Ive just met this evening. He has a fascinating business selling sand to Middle Eastern Companies and, Jo, Lou here and I have been friends for years. He runs a business helping growing exporters raise finance from people who are looking for high-risk high return opportunities. These introductions are designed to get the two of them to talk quickly and with ease and reassurance. Who knows what may happen. You just might have created some potential for both of them? Business networking isnt just about what you can do for yourself, its about what you can do for others. If you help someone, they will remember you when they hear of someone who needs your services. This of course makes it so much easier for you to move on and meet other people. This exercise is what I call parking. Like your car do it carefully, watch all angles and dont hit anything!

So now you have a parked Jo with Lou you have freshened up your drink. You look around the room and you see clusters of people or groups chatting to each other.

Help... What do I do next?

It's easy. Work the room! Look for a group of three people and move over to the edge of the circle. As you are moving towards the group, look at the faces of the people and decide who seems to be the most welcoming. Stand opposite that person at the edge of the group and smile. I can assure you the following will happen. The person you have smiled at will smile back and one or both of the other people will turn towards you and both will take one step to the side making a space for you. When you first do this, it's not easy. I'm not pretending it is but it always works. Ask in a gentle voice "Good evening please may I join you"? Again I have to tell you, you will not be rejected. The chances are someone will put their hand out and introduce themselves. I often play a game at the start of a business networking seminar or prior to a sit down meal by asking my newfound friend if they would allow me to use them as a Guinea Pig. I get them to go up to people they don't know, try out what I have just said and it always works. I do this simply to ensure that whenever I write about the matter or speak about it at the presentations and seminars I deliver that I feel confident in the advice I give.

Once you have successfully joined a group, dont change the subject matter and wait for them to start asking you questions. Bear in mind again, the chances are these people are from the same business or have known each other for a long time but haven't got the self-confidence to break away and meet new people... So you are a big relief for them!

When you are in a group, you will know the time to move on, instinct will tell you. I don't need to. So go to the top of this article and remember the tips about working the room.