It's not a bad idea if you have internet plans. I don't know what you site name would be but some try to make an income from cyber squating. They register all kinds of desired names hoping to sell one for big $$$. I remember stories where people would try to sell names like ibm.com to IBM etc. for big money. I don't know who won those.

One warning about registering the domain names. MAKE SURE YOU ARE THE OWNER AND HAVE CONTROL OF THAT NAME. Some will register the name for cheap. But they register it in their name for you. They control it and you are at their mercy. When you do get a site you need to point the domain name at your site. For that you need to remember where to go, user name, and password. Otherwise you will be the owner of something that does nothing.

If your serious I would register for a number of years. If the name expires it can take weeks or longer to get is straitend out and you site working.

Tom