If you want to access geo-restricted content like TV3 and RTE from outside Ireland then you'll need to get an Irish IP address. By using a proxy based in Ireland you can hide your real location and access all these sites.
Unfortunately there are very few free irish proxies and they come with significant security issues. This video demonstrates using a computer program called Identity Cloaker which gives you access to a network of secure proxy and VPN servers across the globe. This network also contains many Irish servers which can be used to access the Irish media sites.