There are two choices: setup virtual domain on the same IP, set up virtual domain with a new IP.
The first option is the easiest as Apache sorts this out. But is there an impact on speed? What about search engines? Will they penalise links between these sites because they are the same IP?
We are running about 15 domains off a single server using name based virtual hosting and the performance seems fine. Some of the sites are currently quite small but a few are doing a few thousand visitors a day and we have had no problems.
We have had no link penalitises but we don't heavily cross link between our sites.
I hope this helps.
Hmmmm, I think a search engine could figure out you are just next door as well. I would just use one ip address; as you will not be convincing to a smart search engine that you are two different owners either way. No one can hide. And no, they will not penalize you for hosting two domains on one IP. Bad linking and spammy things will be the only thing you should worry about for getting penalties applied to you. I vote for Shared IP.
Ahh, I get the feeling I didn't need to purchase those spare IP addresses after all. Got any other uses for them? :-)
