test = read.zoo("http://dl.dropbox.com/u/41922443/test.txt",
   header = FALSE, sep = "\t",
   FUN = function(idx) as.POSIXct(strptime(idx,
      format = fmt, tz = "PDT"), format = fmt, tz = "PDT"),
   colClasses = rep(c(NA, "numeric", "NULL"), c(1, 1, 0)),
   aggregate = tail1)