Powershell script to import csv data into a List

http://itrob.be/sharepoint-powershell-script-to-import-csv-data-into-a-list/

http://social.technet.microsoft.com/wiki/contents/articles/18830.sharepoint-2010-import-data-from-excel-into-a-list-using-powershell.aspx

http://www.spjeff.com/2012/02/26/powershell-upload-csv-file-to-list-both-server-and-client-om/

http://aidangarnish.net/post/Easily-import-data-from-CSV-and-SQL-to-a-SharePoint-list.aspx

http://office.microsoft.com/en-in/sharepoint-foundation-help/synchronize-a-sharepoint-list-with-a-spreadsheet-program-HA101854204.aspx#_Toc263247006