FOUNTAINS OF WAYNE could have been just another slackerish bunch of boys with guitars playing bummed-out ditties about nothing at all. You know, like the Lemonheads or Weezer. But songwriters Chris Collingwood (center) and Adam Schlesinger (right) are way too talented for that. Schlesinger just got an Academy Award nomination for his title song to Tom Hanks’s ““That Thing You Do!’’ And on ““Fountains of Wayne,’’ he and Collingwood show off a gift for turning low-key tales of office temps and party girls into hummable little masterpieces. ““Sink to the Bottom’’ is about an addictively bad relationship; ““Leave the Biker’’ is about someone else’s addictively bad relationship. F.O.W. (which also includes Jody Porter, left, and Brian Young, not shown) prefers ““big, simple chords,’’ says Schlesinger. ““We’re not into musicianship for its own sake,’’ says Collingwood. ““We once spent an entire show making fun of Eric Clapton.’’ With songs this good, they can afford to.