This is a phase II study of the small molecule inhibitor perifosine (NSC 639966, D21266, KRX-0401) in the treatment of patients with recurrent glioblastoma multiforme (GBM) and other recurrent malignant gliomas. The goal of the phase II study is to determine efficacy as measured by the progressionfree survival rate after 6 months of treatment. Secondary goals include determination of molecular and metabolic effects of perifosine by tissue analysis and PET imaging.