How to customize ubuntu 11.04 Natty Narwhal live cd

There are many ways to customize ubuntu live cd on this planet. This morning I am thinking to customize my ubuntu 11.04 machine in my own way.I wish to additional package needed for me. One of my friend work in ISP and I thought to go over there and download alll the necessary packages required for me and wish to make the live cd my running machine Live Cd for future with these addtional packages. After customizing the size of my live cd , I better call it backup is around 850 Mb. I have used uck (ubuntu customization kit) and Remastersys to customize my ubuntu 11.04 To know how to use Remastersys and UCK, you can google for it and can get many tutorials . Cheers !