Google Docs is a popular online office suite which comes with pretty decent features when it comes to handling spreadsheets and documents. If you already have a spreadsheet created in Google Docs and want to add data from another sheet, Google Docs has now added new feature to the file import function. With this feature, when importing a .csv file, you can create a whole new spreadsheet, append to the current sheet, add a new sheet to your existing spreadsheet or even replace your entire spreadsheet.
It also comes with a new custom delimiters option, so that you can specify what character to parse your data file with, giving you maximum flexibility when dealing with your data files. There is also a preview functionality which means you can see how data looks even before importing them.
More details available here.