from gfan blog I came to know about this site, I am using kproxy and found it the fastest one and always working but I often found it saying that server is overloaded and try some other time.
Any trick to overcome this ?

hmm..

I think you can try visiting a site with kproxy and then bookmarking it. open a site, bookmark that newly opened page in your browser & next time open it directly from browser's bookmark.

For me, I tried this when server was showing overloaded message on and on.. worked for me !