I know this is an old post but I thought I'd share as it directly answers at least one post here.
Tuskify is a service that interacts with your notes in Evernote and can automate many of your workflows and manual tasks. The above is a perfect example of one of the many things Tuskify can automate.
To explain, in Tuskify you create recipes which contain triggers and actions. Triggers are things that Tuskify should look for in your notes before running the actions, which update your notes. For @MPBerz you would create a recipe to look for notes that are tagged with todo (trigger), and add a reminder to those notes (action). This would allow you to quickly add a tag to any notes (in Evernote or the Web Clipper, for example) and have them automatically show in your reminders list.
We've just recently added Zapier integration, so if you wanted your todo's to appear in Todoist (for example) after you tag them, that's no problem
@cyboman I believe your request is slightly different to the above so we'd certainly be willing to hear what you'd like to achieve and discuss how Tuskify can help.
Disclaimer: I work at (and co-founded) Tuskify. We created Tuskify because we love Evernote but wanted to have more flexibility and automation - so we did something about it!