I always heard that they could accept something in value like a coffee mug, or a T-shirt.
I'm not sure what it is. Most private business has a fairly low limit - $25-50, whether anyone adheres to it or not.....there are rules. I did find this piece of information that was passed last year (I think with a democrat legislature.)
2010 Legislative Session Roundup: Indiana
Ethics: The Legislature made important headway on ethics as well by passing HB1001, which will require legislators who leave office after 2011 to wait at least one year before entering a lobbying practice, prohibits lobbyists from funding out-of state travel for legislators, and reduces the threshold for lobbyist reporting on gifts from $100 to $50, and requires legislative liaisons of agencies in the executive branch of state government and of state educational institutions to report annual expenditures.