One advantage that Springpad currently has over Evernote is the ability to send alerts when (or before) tasks are due via email and/or SMS. If you're going to use your application as a place for to-dos, especially those with deadlines, the ability to send yourself a reminder is a real plus.

Another thing I found useful is a sort of alternative UI that Springpad offers called the Board. This is a virtual bulletin board that lets you arrange notes, links, tasks and so on under labels for easier browsing. It's only a single page, so you can fit only a limited number of items on it, but I found it very helpful for scanning my daily tasks.

To capture all the data you come across in life, it makes sense to extend these applications beyond the desktop. Both offer mobile apps for a variety of platforms as well as handy browser add-ons; Evernote also integrates with several third-party hardware and software products.