My Townlands page contains a few examples of third party websites that are a great help at finding townlands and I am delighted to have been able to add another great one to it recently - OpenStreetMap for Ireland. Brian Hollinshead gave a talk to the Ireland Branch of the Irish Genealogical Research Society on the subject of maps for genealogists and highlighted this site in his handout amongst others (see this IGRS page.)
The OpenStreetMap tool has a number of different layers that you can switch on - I particularly like the townlands and parishes options - so simple and clear. The image below shows this on the modern road map version that is accessed via the link above, but there is also a version based on older historical maps, which will be great for finding farms and features that might not exist anymore.
I'm still happily playing around with this site - you can literally zoom all over Ireland. As yet I haven't found a search facility, so you might have to use one of the other websites I recommend on my Townlands page to get an idea of where to zoom into. Watch out for alternative spellings and even some alternative names - always fun with Irish townlands. This is a marvellous open source project, so you can get involved too - see the OpenStreetMap home page for more details.