  In this paper we present the \emph{Distributed Overlay Anycast Table}, a
structured overlay that implements application-layer anycast, allowing the
discovery of the closest host that is a member of a given group. One
application is in locality-aware peer-to-peer networks, where peers need to
discover low-latency peers participating in the distribution of a particular
file or stream. The DOAT makes use of network delay coordinates and a space
filling curve to achieve locality-aware routing across the overlay, and Bloom
filters to aggregate group identifiers. The solution is designed to optimise
both accuracy and query time, which are essential for real-time applications.
We simulated DOAT using both random and realistic node distributions. The
results show that accuracy is high and query time is low.
