I've not heard (and don't think) that it's rude not to have a land line. I have lots of friends who are cell only.

I've had some folks get a little PO'd that I won't give out my cell to everyone. However, most people don't respect limits and I'd prefer not to have my cell ringing all the time (I also unlisted my number and have requested that all companies with whom I do business not telemarket to me). One that comes to mind was a credit card company. FWIW we finally gave it to them (since they kept mistakenly detecting fraudulent activity on our account and suspending use for example when we were on vacation, when we had called to tell them we would be travelling). Wouldn't you know - they didn't call the cell because "they weren't allowed to telemarket on it." Common sense and credit card companies do not go together...