There's one thing about Open Source tradition that everyone should know and care about.
This is specifically for the people who are actively (or maybe not that often) ask questions on Q&A sites (like stackoverflow.com) and other development forums.
The person who answers you, is certainly knowing a particular thing better than you, in some cases knows MANY things better than you. This is the only reason he's able to answer you and perhaps get you out of your biggest problem of the day.
He's sharing his hard-earned knowledge with you, for free!
For which he could have earned serious amount of money if he was selling it. But the spirit of collaborative learning is what drives him.
That's how OpenSource things work.
Consider the case when there was nobody to help him, he dug out things himself, and now is ready to share.
For all this favour, he at least deserves a warm thanks, or at least attention when he's waiting for you to respond.
I have been active into Java and now Android for quite few years, and am seeing as Android is rapidly gaining success, many and many people are jumping into Android development, and obviously, are heading toward forums and Q&A sites for help.
But many of them have behaviours which hurt a lot.
You, as a person asking for help, must understand that you are being given knowledge that can help you gain competitive advantage over your peers in a certain area. Your problems are being solved, your project bottle necks are being resolved, all for free. So you at least can be nice to him, be attentive and respond frequently.
Please ask questions nicely. Provide as much information as you can, thank the person helping you.
If you're in chat, try to be friendly and have appropriate amount of gratitude. Please.