Take A Swim Out of the Mainstream February 26, 1993 - The Times-Picayune By Staff Phish Tuesday and Wednesday, 9 p.m., Tipitina's, $12 No one is sure exactly what's going on here, but Phish is almost phamous. The Vermont-based neohippie band has benefited from no radio or video exposure, but the band regularly sells out 3,000-seat theaters and has to do two-night stands in towns where halls big enough to accommodate all the Phishfolks aren't available. To anyone familiar with the Grateful Dead, Phish might seem like deja vu, but with a better handle on non-Dead material. Phish moves easily - from the Allman Brothers to Vanilla Fudge, from Johnny Cash to Flatt & Scruggs - and often. If the top-flight musicianship and improvisation aren't sufficient acrobatics, the band sometimes uses an onstage trampoline. Definitely not darlings of Madison Avenue, the folks in Phish rely instead on a computer network - called Phishnet (what else?) - and a telephone hotline to get the word out. It's working.