Title: Idempotents and Landweber exactness in brave new algebra
Author: J.P. May
Classification: 55N20,  55N91, 55P43
Address: Dept. Math., University of Chicago, Chicago, IL 60637, USA.
E-mail: may@math.uchicago.edu

We explain how idempotents in homotopy groups give rise to splittings
of homotopy categories of modules over commutative $S$-algebras, and 
we observe that there are naturally occurring equivariant examples 
involving idempotents in Burnside rings. We then give a version of the 
Landweber exact functor theorem that applies to $MU$-modules.
{Appeared in Homology, homotopy, and applications 3(2001), 355--359}