Describing itself as an app that supercharges contacts, Rainmaker is able to automagically pull information about people in your Gmail address book from the web, Twitter, Linked In, and Facebook. This information includes mugshots, addresses, phone numbers, and Internet details. Some of it is publically available data and some you have access to because you friended the individual on Facebook, for example.

The process of seeking-out information is referred to as "raining on", and each time it's used a raindrop is spent. You get 10 of these free of charge when you sign-up, so can dig the dirt on 10 contacts, but you can buy more via for as little as $9 per month.

All the data sought-out by Rainmaker is automatically imported into Google Contacts, which can be accessed from within Gmail by clicking the Contacts link above the Chat box. Rainmaker works with Google Apps for Domains too.

The best way to describe Springpad is as a supercharged notebook and To Do list maker. Because it's a cloud application, your data can be accessed from anywhere in the world, and the app is built around HTML5 so will work on the majority of modern browsers, phones and smartpads too (although too).