The community of Franciscan nuns at Compton Durville, near Yeovil, has published its 2008 programme on the web, and you can find it here.
They've also added an Advent Quiet day to their December programme, on Weds 5th December, details here.
Whilst we're on religious communities around Yeovil, here are a few links:
Hilfield Friary Franciscan monks, north Dorset. They seem to be downsizing, but still a going concern.
Compton Durville website Somerset
Chantmarle Christian centre, Dorset. Most of the pics on the website are of the hotel, the conference facilities are a little bit more functional! However, this still gets well used by local churches.
Mill House Retreats gorgeous little place for individual and small group retreats. Just off the M5 at Tiverton
Abbey House Glastonbury with the added bonus of a great view over the Abbey ruins.