As well as spoken prayers, we have silent reflection at Church when we are supposed to remember our loved ones in spirit or be thinking about people on the healing list. Silent reflection could be just that ...  or it could be just a time when peoples thoughts wander into what they are planning for tea (ie we can get distracted).

I personally can't see a problem with prayers before meetings. Those who don't believe in God can still surely respect that others do and that they have members of their group that do. It doesn't mean they have to join in with the prayers or be offended by them.