Weave, by Intuit.com, is an interesting task manager app. It's visual design is nearly perfect, which is a great hook to make you want to try it. It's free, so it won't hurt. But there's some things about it that just don't work for me.
The app will not function without you registering at the Weave web service. While I have no reason to think anything nefarious is going on there, Weave is the only task app I know of that requires you to register. What are it's developers doing with that information? I don't know.
Once you've registered, you're confronted with some tutorials on Weave's use. You can't skip the tutorials. This is, to me, the developers saying "You're an idiot and you can't be trusted to use this app without proper training."
Finally, once you've set everything up, the app seems to sync every time you start it. It syncs in the foreground, thereby locking the app for a good five seconds or more. Every time you start it. This can really slow a user down if all they want is to fire off a quick little reminder.
As I mentioned, there's some great aspects to Weave - you can see them all by going to my comparison of iPhone task managers. But there's enough hangups with Weave that I really cannot recommend it.