OK if you need more details go here http://www.culturenight.ie/listing.asp?id=4
Sorry for late notice but I only heard about it this weekend - if its any help last years winner did a poster depicting the luas passing by the four courts based on a graphic style of the 1940's encouraging people to use the luas to visit the city of Dublin - looks as though it was done probably through a vector based programe like adobe illustrator - not a criticism just an observation so you can picture the level of polish involved in that winning entry but it didn't leave room for a more human touch, a more human line...
So yes it's a good pic and yes it was run through a computer so they had a particular computer based style, shouldwe fear a computer,no, I say go for it with or without a computer - but get a good diguital pic of whatever you decide to do and send it in.
They require both a portrait and landscape compatible format of the same picture. Details of the rules can be found thru the link http://www.culturenight.ie/listing.asp?id=4. G'luck.