Evernote is one of my favorite platforms. It's more than an application and more of a system, so platform it is. I have blogged about it before, so if you aren't a user, go check that post out. I use it daily, and they keep adding features and improving the ones they have. Evernote is one of the few products I rave about that is not only for Macs or iOS devices. It works on anything.
Evernote has been around long enough that an increasing number of third-party vendors have made it even more useful. I've spent more money than I probably should on iOS apps that simplify getting data into Evernote via that route. It isn't really that complicated, but I passcode mine, and that 0.005-second delay is just too much, apparently.
Powerbot solves a problem. I frequently get e-mails that I want to get into Evernote because they are part of a project. Before Powerbot, I forwarded them to my Evernote e-mail address. That works, but it looks tacky. Then there's the Evernote Web clipper, which in its latest iteration does make clipped Gmail notes look nice (Powerbot works with Gmail, Outlook, and Yahoo!, according to the Web site, I should mention). Still, Powerbot adds more features than the Web clipper, makes e-mails and threads look prettier, and adds "archive after sending" options.
For Mac users, Powerbot has a plugin for Mail.app that allows sending one e-mail or a thread of e-mails, saving attachments to Evernote, and archiving an e-mail after sending. You can add tags and comments. It's very handy and nice.
There are also Powerbot offerings for Dropbox, Gcal, and, inexplicably, Google Reader. I don't have a need for those, but all of them have a 30-day free trial, after which you can purchase the services for a pittance. It offers monthly or yearly prices, mix and match, depending on which services you want. I paid about $14 for a year of Powerbot for Gmail only.
At first blush I thought the idea was interesting but silly because you can find anything immediately by searching Gmail. Then I remembered that for most projects, I have non--e-mail stuff in Evernote too. Powerbot is simply a streamlined way to usefully and visually pleasingly shoot e-mails into Evernote into the correct notebook with tags and comments in one step. For the grand price of nothing, it's worth a try.