  The shortest distance around the Universe through us is unlikely to be much
larger than the horizon diameter if microwave background anomalies are due to
cosmic topology. We show that observational constraints from the lack of
matched temperature circles in the microwave background leave many
possibilities for such topologies. We evaluate the detectability of microwave
background multipole correlations for sample cases. Searches for topology
signatures in observational data over the large space of possible topologies
pose a formidable computational challenge.
