Catholics: Does God ever speak through priests?

It depends a bit on what you mean by speak. If you mean in a literal way, like a ventriloquist putting his own words into the mouth of another, then I have never heard of such a case (although I don't deny that it could happen if God chose to do it).

If God were to speak through a priest, it would be more likely that he would do it in an indirect way. He would make his words know to the priest, perhaps through a vision or locution (interior voice) and prompt the preist to repeat or publicise the message. This approach is more akin to God's usual way of working, in that He would require the co-operation of the priest rather than compelling him to speak without regard for his own will. This sort of thing is what happened with the Old Testament prophets, and with some Christian mystics such as Julian of Norwich or St Faustina. I don't know for certain that this has happened with any priests, but I suspect it may have done in the case of some of the more mystically gifted ones (perhaps Padre Pio or St. Jean Vianney, for instance).

There is also the matter of God speaking through the church as an instituion, which is a slightly different thing again. It is a belief of the church that it will never fall into error when the Pope, or the bishops in council, make a declaration on faith or morals. In these cases it is not that God explicity tells someone what to say. It is more a case of guiding events with little nudges here or there so that the end result is correct. It could just be a case of a nagging doubt about something which makes a Pope hold back from speaking ex-cathedra, or an unfortunate illness which prevents a maverick bishop attending an ecumenical council. No one individual will have been directly spoken to by God, but the end result will be his word in a looser sense.

God is speaking through everyone who speaks the Truth, including priests of course.

God speaks through whoever He wants to speak through. There will be times in your life when He will inspire You with what He needs to say to someone through you. Listen for His words.

Yes

Through preist and ordanary folks like us too.

Most definitely!

I'm not a catholic but I can answer this anyway.

Even if God does... can you ever really believe a person who says "So I was talking to God the other day..."

How do we know? You can't ask questions like this. We can't tell, even if the priest says so.

i'm sure He does.