With so many long-distance options, it's hard to pick the plan that's best for your company. Twice a year the Telecommunications Research & Action Center (TRAC), a consumer group in Washington, D.C., samples about a dozen small-business plans from six leading long-distance providers. TRAC compares prices for a set sample of calls, at levels of usage ranging from $150 to $6,200 a month. TRAC's research provides a good starting point for comparing long-distance rates and plans. For a copy of "Tele-Tips Business Rate Comparison Chart," send $5 and a self-addressed, stamped legal-size envelope to TRAC, P.O. Box 12038, Washington, DC 20005.