I read more and more often the user switch to the pure webmail, preferably to that of Googlemail. Email clients are a fine thing, you have the mails on your own computer – who wants, uses the whole with imap and also has the mails written at home at hand at all times. However, if you want to completely detach yourself from the client, you have to access a web interface. The disadvantage is that you either have to stay logged in all the time (to see when new mails are there) or you have to log in each mail. But with a webmail email Notifier, you can immediately see when there are new mails without being logged in.
With GWatchman, it's all easy. After a short setup of the Gmail account, it can start right away. You enter the Googlemail account data, decide how you want to be notified (for new mails) and then the whole thing runs.
You can tell where the notification window should be, whether it should be at the top of the middle, top-right or bottom right. Integration options with Growl for Windows also exist if you want it to be consistent. The only drawback, in my opinion, is that you can only enter one account. Thanks for the great contribution of Caschy, I knew so far only Spiffy and 2-3 other tools.