Do you think calling someone up to just get someone else's no. is rude?

I would be offended in a way. Knowing that someone only called me because they wanted my friend/roommate's number makes me feel like they were using me. But if I was at the other end of this, if I had no other options...I'd only be able to ask that person for the information. So I'm split on the issue.

To some extent it does bother me that the person never bothered to call me up before and now is calling out of necessity! anyways i will give him/her the number but first i will ask the person whos number is wanted!

Yes! Especially since you have no idea what their intentions are for calling. here is a recent incident I had been made aware of. I have a friend who is also an old friend of a family memeber of mine. My family memeber has been troubled for sometime. I thought it would help if she was reaqauinted with her best friend from her childhood. I made sure each of them wanted to communicate and gave ach of them phone numbers for each other. Things seemed great. I recieved an e-mail from the friend asking me if I was aware that my family member had called someone she got another number from the friend and called to harrass this other old friend. She made it seem as though she wanted to catch up with her too and she called and made threats! I also had a co worker if you will give my number to a new male employee he claimed I was going to give him a ride home. He ended up finding my house from it. I told my supervisors of the situation. He was terminated soon after. No. Never give out a number without calling that person and making sure they want them to have it.

It doesn't really offend me or bother me, but I never give out someone else's number without calling them first and asking if it is OK. This is a courtesy that I would love to receive from others, also, but so often somebody just hands out my number to somebody that I wouldn't really want to have it.

No, this is no reason to feel offended. I don't think its rude at all.