Which memory will work dual channel with stock Dell stick?

[overst33r]

I have 512MB installed from dell, will either of these work in dual channel?

http://www.newegg.com/Product/Product.asp?Item=N82E16820231038 or http://www.clubit.com/product_detail.cfm?itemno=A4308030&cmp=OTC-pr1c3grabb3r

Thanks for the help.