I did recommend the nameservers :icon_redf I've never done it with the IP, let me know how to do it Jeff it may come in useful for some of my sites!!
You can only do this if the company you bought the domain from will let you use their nameservers to point to external sites.
I have most of my domains with 123-reg, and I prefer to use their nameservers so I can just change the A records, and continue to use their email forwarding system.
If you use 123-reg, just go into the control panel for the domain, click on Manage DNS, then change the A records to point to your IP address.