I just registered a domain on 123-reg.co.uk for my portfolio site, and have registered as 'UK individual' and the site is prompting me if I'd like to opt-out of the WHOIS system - would this be a good idea? I haven't a clue!
It simply means that your details won't be displayed when people search the WhoIs records at Nominet on the domain you're registering. It's just down to personal preference really as a UK individual, do you want your address and e-mail listed on the records? or would you rather have them hidden? I'm guessing you'll have your address on your site contact page anyway?