How do I acquire a domain owned by someone else?
There are only a couple of ways you're going to be able to acquire that domain. Firstly, by getting the owner to sell it to you. Alternatively, if you can prove that there is a legitimate reason why you should own that domain rather than the present owner, such as a trademark, you can file a Domain Name Registration Dispute with ICANN and let them decide who should own it.
However, if the only reason you want this domain is because you like it, and the owner doesn't want to sell it, then you're pretty out of luck. The owner may not be using it, but that's his choice.
If you do file a domain name registration dispute with ICANN, be absolutely certain your claim is ironclad. Also keep in mind that this will (last I looked) cost you around $1500, which is often way more than the person who owns the domain would ask to sell it to you.
If you do intend to file a dispute, see if you can get the person who currently has the domain to make an offer to sell it to you first. This generally helps prove bad faith if they're also not using it (it's parked or something).
If it expires in a few years, don't even think about messing with the domain backordering services. Their function is to register the domain for you faster than the other domain backordering services, and/or the type-in public. They're generally a waste of time to begin with, since they can only help you after both the registrant and the current registrar have allowed the name to drop. If it's a good name, many registrars these days don't allow the name to drop to the public level at all, instead keeping it and putting it on auction.
Also, if you haven't already, stop going and visiting the domain name in your browser. Any kind of typin traffic increases the value of the domain name significantly. If your customers are also typing in the domain, do your best to get them to type your current one properly. If you can lower the amount of traffic to the domain before you make an offer, you'll almost certainly get a better deal.
If you do plan to make an offer, try checking to see what other domains the owner has, and start by inquiring about some other one. When they quote you a really high price, act uninterested, and inquire about several others, including the actual one you want. As others have said, avoid any association with your real domain.
If you do get in touch with the owner, and they're willing to sell, usually they'll quote some astronomical starting figure (often 5-10k for middling-bad domains). This is fine, offer them a lot less. A good rule of thumb is to aim for a final selling price of 10% of the initial request.
Try emailing the email in the whois address.
I occasionally do this for my employer and about 75% of the time, we receive a reply back with someone willing to sell. If you're worried about using your company's domain in the email, make a gmail account. That's what we do, but I can't say whether it affects the price.
Most registrars will offer the services of attempting to obtain the domain for you. When you do a WhoIS lookup on Network Solutions, and the domain returns as being registered, they will offer you options on how to obtain it.