Really useful web sites for panicked observers

ADS
airmass (incl. UT/local time conversion)
astro-ph
astrophysical calculator
magnitude/flux calculator
moon phase
sunset and sunrise
NED
planetary positions
RA-dec converter (coco)
radial velocities
SIMBAD
skycalc
.....every conceivable software package!
Search NED, SIMBAD, ADS from target name/position