30 second introductions should be more than sufficient. It can be difficult to summarize what you do in such a short window, but remember what you do may not be what they need. Target your pitch for your audience. Include something that gets a laugh or is attention grabbing. 
"Given the social climate these days it may not surprise you to learn that one in three homes in the United States is bugged! That is right BUGGED! Pest control is just a phone call away. We offer 7 days a week service" 

A method that I have found to very useful with my clients is to present your introduction and have someone else then explain to you what you do. This will show what part of your message is truly being conveyed and what, if anything, stands out about you or your business.