There is a site on the web devoted to finding out the history of your surname and what is the Irish Equivalent of you surname. It's a pretty spartan affair, but the website is very easy to use.

You can find it here: Sloinne 

Thanks to the Irish Central website for the tip

From the website:

Welcome

'Sloinne' is the Gaelic translation for 'Surname', the purpose of this website is to develop a comprehensive on-line database of Irish language surnames and their English versions with the aim of promoting the use of Irish surnames by the general public and in the worldwide Irish diaspora.

This project was developed with the assistance of the body responsible for the promotion of the Irish language 'Foras na Gaeilge'. Where available we will also include information on the history and origin of names. User contributions are welcome.

Surnames are provided by the following sources:

• Sloinnte Gaedheal is Gall 
• An Sloinnteoir Gaeilge agus an tAinmneoir