The ultra-high energy frontier is Mandlestam's $s>TeV^2$, where ordinary
physics does not work any more.  Exploring the physics of just one
particle, the neutrino (or is she three, or six?), many prospects or new
discoveries exist.  We will present three topic(s). In radio detection
of neutrinos, we use the lowest $s$ to measure the highest.  Then the
GZK problem, which is the $s$-iest combination of all letters.   Finally
we consider a new form of neutrino oscillations, that might be really
$s$-y, if only it is found.