  The evolution of spherically symmetric unstable scalar field configurations
(``bubbles'') is examined for both symmetric (SDWP) and asymmetric (ADWP)
double-well potentials. Bubbles with initial static energies $E_0\la E_{{\rm
crit}}$, where $E_{{\rm crit}}$ is some critical value, shrink in a time scale
determined by their linear dimension, or ``radius''. Bubbles with $E_0\ga
E_{{\rm crit}}$ evolve into time-dependent, localized configurations which are
{\it very} long-lived compared to characteristic time-scales in the models
examined. The stability of these configurations is investigated and possible
applications are briefly discussed.tic time-scales in the models examined. The
stability of these configurations is investigated and possible applications are
briefly discussed.
