I am looking for an application to track my time spend on different projects. Let's say I have about 3-4 project and in every of them I work on 5-10 tasks. I often switch between the projects, so it must be easy and quick.

So my requirements:

* multiple projects
* simple switching between tasks and between projects
* some monthly reports (and possibility to export them)

I don't need much more — some pretty charts would be nice, but not necessary. It would be also nice to share the reports, but I can download them and send in the mail, no big deal.