17-04-2007 - 18:12
I don't imagine the Interrail pass would not alow you to travel from Belfast to Dublin, Ireland is pretty much considered as one country in these matters.
However, if not, you can catch the Aircoach, which is a bus that travels from the centre of Belfast to the centre of Dublin and it's very cheap. I think its around £12 for a return ticket.
If you need anymore help in this give me a shout as I live in Belfast.