Copyright or trademark infringement on web site name

I'm about to place a site I've built live and looking at registering a domain name.

Is there anything I need to worry about in picking a name?

If my domain name is a misspelling of another domain and our business is different, am I at risk? I'm thinking of something general like speakor.com vs. speaker.com, not like mispaces.com or friendbook.com

(note: I don't know if the above domains exist or contain suitable content, just making up some random examples)

Is it likely we would be asked politely to change our name prior to legal action?

Provided you're not talking about one or two letters misspelling difference and provided you're not ripping off another sites design/colour scheme, I'd say you have nothing to be worried about.

I know there is law somewhere stating that you're not allowed to register and operate a website that is a deliberate misspelling of another domain and you can get sued and lose ownership of your domain if caught doing so, especially if you're building a similar site to the one you're using a misspelling of.

Say for example you register; faecbook.com or faceebook.com and then start a social networking site, you're pretty much going to lose any court case Facebook brings against you regardless of stature or who has the most money.

It's why a lot of counterfeiters for physical goods get caught and shut down because they're imitating a product and always mostly using a deliberate misspelling.

I would advise personally against registering and building a brand around a deliberately misspelled domain name, it's not worth the time.

Just come up with something yourself, there are many many domain extensions you can creatively use to come up with a great domain name. I personally use: http://domai.nr/, which generates some unique domains and shows if they're available or not.