Ireland. Man I'd love to go back there sometime. I toured ireland on my mountain bike convert a year or two ago. It was pretty amazing. We did about 50 miles a day for two weeks then we locked up our bikes in some ladies shed and hitch hiked around for the next two weeks. The weather was great when we went as well. I don't know what your plans are, but I'd say you pretty much have to do the west coast. It's beautiful and there's a lot to see.
If there's one place I'd say you *have* to go it's the dooey hostel in glencolumbkille (http://www.dooeyhostel.com/). Mary (I hope she's still well) is an older lady with more character than anyone I'd met before that. She's also incredibly sweet and curses like you wouldn't believe. The view is absolutely amazing and the town has a really good feel to it.
george, if you want to plan it on a computer, a website i was recommened, and i used it lots, was www.bikely.com
You can plan the route, and it adds rough distances, more correct the more detailed you make the route!! Also you can make it public, so others can see it!! Once you figure out how to send a mail on this website, send me one with the towns you plan to go through anyway... or even post it here if you want it public!!