Going to meet the local business owners in their own realm is the best, as far as I'm concerned. Just take a day or two each month to make the rounds. Introduce yourself with something like, "I thought it would be beneficial for us to become acquainted" and keep it under five minutes. If they have a small staff, make an impression by bringing the favorite local donut or something similar.
Be consistent in stopping by to see how their business is going, what's new, etc. and they will know who you are very quickly. If you have a new listing, or know of some zoning or governmental issues that will affect them, drop that information off with them. Send it to them in a note. Multiple touches through different medium will create a more long-lasting impression.
Most business owners I know would prefer that to going to some BS networking group where people just want to exchange cards. If you show interest in them, they'll show an interest in you.