I am finding my students are increasingly using spreadsheets to solve mathematical problems in class and represent their data and findings in meaningful ways. There are a few options in the spreadsheet market including Google Doc's, Apple's Numbers but the king of all spreadsheets is still Micorsoft Excel.
I came across these great tutorials on using Excel in the classroom and would highy recommend them to others. they include advice on using spreadsheets to assit students and teachers in maths and science and also in creating graphic organisers. Loads of great lesson ideas and there are even ready made workbooks for you to download and begin using straigh away. Check it out here.