Annoyed that Google Talk doesn't work anymore and you have no idea when you have new messages in your Gmail inbox? I was, so I made an app for that. Gmail Checker is a simple application that runs in your system tray watching your Gmail inbox for new messages. When it sees one, it changes its icon to the icon from Google Talk that notified you when you had a new message. It also slides up a window that looks very similar to the one Google Talk displayed when you had a new message. The main difference is that it doesn't put the email content in the popup, it's just a numeric notification.
For some reason, Google has been waging a war lately on native applications and moving all their features into their Chrome browser. That's their prerogative, they can do whatever they want with their own services and products, but there are people out there, like me, who do not want to use Chrome. I find it a bit silly that they only disabled their own client, which could have continued running without support, since they did not discontinue the underlying infrastructure, but that's neither here, nor there. The only other alternatives I could find are plugins for other web browsers like Firefox, or applications from shady websites that attach malware to them. I have the ability to roll my own, so when I can't find a solution I think is reasonable, I usually do. That is the case today with Gmail Checker.
You can grab the latest version from the application page or just download it directly. It does not require installation, it's just a zip file that you can extract anywhere. If you have any questions or comments on the application, please contact me and let me know!