Download Links for YouTube Mobile Application:
Internet Profile and Java Setting: Smart Internet
Proxy and Port: 126.96.36.199:8088
Streaming Setting: Smart Internet - No Proxy
You can also download and install YouTube mobile application directly from the default browser of your phone by going to m.youtube.com. Make sure that you have changed the proxy settings before you download it using the default browser to avoid charges. Another way to download is to use Opera Mini mod v3.10 by using the wap.smart.com.ph@ download trick.
This is working 100% on Sony Ericsson K800i.