Dropbox is a versatile tool: it's used for backing up, syncing and file-sharing, but it's not without its drawbacks. Like any other folder on your Mac, you only know something has changed when you manually check it. That might not be a problem if your Dropbox folder is kept for personal use, but if you're using it as folder repository for the purposes of collaboration or work, you might wish you were more in the loop with any new or updated files that arrive from other sources.

What you need is some kind of notification, alerting you to any updates to your Dropbox folder. And guess what? We have just the solution -- if you're a Mac user at any rate -- in the form of the small, but perfectly formed DropIn. It offers an elegant and highly configurable means of keeping you fully informed. And at just $1.99, it won't break the bank either.

Once installed, DropIn will ask you for the location of your Dropbox folder. And that's it, if you so wish: it'll place an icon in the menu bar and provide a suitable notification (fully customizable of course) whenever an update occurs. You then click the program icon to view a feed of all recent changes -- roll the mouse over an item for a preview or to open it for further investigation.

DropIn allows you to create filters that make it possible to monitor selected files, folders or file types only -- perfect if you're only interested in checking out specific shared folders, for example. You can also create Smart Folders, which appear above the main feed, allowing you to monitor multiple updates from different parts of your Dropbox folder.

Throw in a feature called Droplets, which allows you to quickly copy files to a specific Dropbox folder simply by dragging them onto the program's menubar icon, an option to automatically upload screen captures to your Dropbox folder, and you have DropIn in a nutshell.

DropIn 1.0.1 costs $1.99 and is available for Mac users running OS X 10.6 (Snow Leopard) and -- in case it needs to be said -- Dropbox.