Nokia Play To lets you play media stored on mobile phone on a TV screen or with a home audio system. All devices including mobile must be connected to the same WLAN.
You can show photos and videos taken with your mobile to your friends wirelessly on your TV. You can listen to your favourite music stored on your mobile with your home audio system.
“Nokia Play To” supports DLNA capable playing devices such as TV, A/V amplifier, Blu-ray player or PS3 game console.
Just launch Play To, select the device and media you want to play. No configuration is needed once WLAN is on and all devices are connected to the same network. [source]
Visit Nokia Beta Labs to try it out.