It takes a lot to get me to post twice in one day (OK, sometimes it takes a lot to get me to post twice in one week), but I just got an email from Citibank and wanted to pass it along.
They've been trying to get me to convert from paper statements to electronic statements for a while, but haven't offered much incentive, so I haven't bothered. But they've launched a new program -- for every person who converts to electronic statements, they'll plant one tree. (If you care about the details, they'll actually make a donation to the National Arbor Day Foundation towards the planting of one tree.)
If you're interested, there are also organizations like Green Dimes that say they'll cut down on your junkmail, helping avert wasted paper.