Hi,
I just wanted to clarify what does a wildcard do.

Basically if i had wildcards enabled I'll be to point my browser to steven.portfolio.com and it will point to the same server as portfolio.com.

So if I wanted to setup lots of subdomains, all I have to do is to configure my server to serve the appropriate page for each subdomain right?

What I want to do is have a domain for my home web server. I'm self hosting a site.

Do all 123reg allow wildcards?

Correct. Wildcards match against the hostname. WWW is a hostname too.Correct. You can use apache rewrite rules to redirect to specific pages, or set up virtual name based hosts each with their own web root directory. The virtual hosts is cleaner and easier to do IMHO.You've checked that your isp doesn't block port 80 and whether you have a dynamic or fixed ip address ?
If you buy a domain name then you can have whatever DNS you want including wildcards. If you are using someone else's, like DynDNS then you get to use wildcards on their provided domain. But that will usually take the form *.host.domain.com where host is your chosen DynDNS name and domain.com is shared by many others.

Thanks alot I'm running a dynamic ip BUT o2/be there assign their ip based on a mac address. I've been on O2 for over a yr and my ip has NEVER changed! They charged an exra 5quid a month. I'm too cheap to pay lol.

I'm on Be and I get a free static ip included (Be Unlimited). No port blocking either ...

oh I'll have to investigate that.
I've just spoke to 123reg they said that despite the wildcard I'll still need to buy subdomain (which are expensive!!). Is this true for all providers?
I was under the impression wild cards enable steven.portfolio.com but I don't need to register it because it's based on the wild card.

How expensive is expensive ?
I have my domain records hosted on nettica.com, it's only $10 per year for one domain. I actually have bulk hosting which is 50 domains for $50 a year.

You can add and change your records as often as you want and create subdomains (new hosts) for free.
I have all my sites hosted on my home server now, as it's cheaper. My mx records are pointing to gmail (also free).

They charging me 9.99 GBP which am assuming is per annum. They didn't say.

But technically the whole point of wild card is so that you don't need to register subdomain because it's based on the wildcard right? So if I wanted steven.portfolio.com , I don't need to purchase that as a subdomain right?

So you just have the one record then everything matches to the same IP

If your on a budget you could set up 'steven' as a valid hostname in DNS pointing to the same IP. You can set up Apache to handle this 'hostname' as a 'subdomain' using a simple virtual host directive. It would see the hostheader 'steven.portfolio.com' and direct it accordingly.

For example:
Works just fine for a single host that appears in a browser as a subdomain would. Before you spend a penny on anything this may suit your needs. It's not the 'perfect' answer because individual hosts can't be dealt with (such as mail.steven.portfolio.com or www.steven.portfolio.com) - but it's a cheap way for dealing with just web traffic if it's all you need.

HTH