Android/iOS/WP7/Web: Speek is a new, free conference calling service for easy one-on-one or group calls. You can also share files and keep track of participants using its web and mobile apps. You don't have to remember a PIN, download plug-ins or jump through hoops -- just click a link and you're in.
Speek's biggest feature is that you can create a custom URL, like "speek.com/alanhenry" and give that out to anyone who wants to join a call you're hosting. All they have to do is click the link in their browser to join via their computer, or to immediately hop in on their smartphones, either through the Speek app or by dialling right in. Similarly, when it's time to start the call, you can use your own URL to hop in too.
Once you're on your call, you can share files with other participants, record the call for posterity or future reference, see who else is on the call with you, see who's talking, mute other people, IM others via the web or mobile apps, have side-conversations where no one else can hear and so on. It's a pretty robust set of tools for people who need to schedule conference calls but don't want to pay a lot of money for a premium service.
Of course, it's not perfect -- depending on your needs, Skype or Google Hangouts may serve you just fine, especially since they both offer screen and document sharing. Plus, services like Uberconference offer similar features.
Speek has browser extensions for Chrome and Firefox to make joining and managing your call easy (although technically you don't need them), and mobile apps for Android, iOS, and Windows Phone. It's free for individuals and calls up to five people. $US10 per month gets you Speek Pro, which adds the ability to record calls, integration with Dropbox, Box, Evernote and Google Drive, and unlimited attendees. Hit the link below to learn more.