[icann.org...]
Unfortunately a new globally accessible TLD isn't something you can just buy off the shelf - normally you'd have to put it through DNSO, at which point you require the cash to help petition your cause and of course convince them that you are a capable of running such a system...
[dnso.org...]
- Tony
You can buy widget.shop, widget.law, etc, etc from them (no .gum yet). The problem is that since these are all totally unofficial, the domains only work if the potential web surfer is connected through a new.net friendly ISP or have installed the new.net plugin (it used to come bundled with a number of freeware products). Although they claim an astonishingly high base of new.net-enabled users, anything less than 100% uptake makes their product essentially worthless.
You could do the same thing yourself by setting up a DNS server that resolved .gum domain names ... and then convince the owner of every other DNS server on the planet to route requests to you.
If you just want to do it to amuse yourself, you can add an entry in your hosts file on your PC.