Snarl - Snarl is a notification system for Windows.
Pushbullet - Pushbullet - Your devices working better together
Notifu - Notifu, a free open source pop-up balloon utility
Kopy - Kopy is the best way to copy/paste your text across your devices.
Notify OSD - Canonicals on-screen-display notification agent, implementing the freedesktop.
QPush - QPush is a free service that lets you easily push text and links from PC to iPhone.