I use Dropbox on nearly a daily basis and love its OS X client that lets me grab files I have uploaded from my iPhone right from its menu bar icon. This client is less useful if I want to upload files from my Mac or share a folder or files. With the QuickDrop extension for Chrome, I get easy access from the browser I use every day. Here's how it works.
After installing the extension, click on the "Q" button that it places to the right of your URL bar, then sign into your account and allow the app to access your Dropbox files. You'll be taken to a settings page where you can choose a folder for uploads made with the extension. You can also tweak a couple of formatting options and select how to handle duplicate files. One note on choosing the upload destination folder: you must choose an existing folder.
After the setup process, the next time you click on the "Q" button, you will see your list of Dropbox folders and files. For each folder, three actions are conveniently located to the right: Get link to share, rename, and delete. You get these three actions for individual files, too, along with a download action, but you can just click on the linked file name of any file to download it.
In addition to supplying quick and easy access to your Dropbox folders and files, QuickDrop provides two other useful shortcuts, one for downloading and one for uploading.
It adds an item -- Download to Dropbox -- to your right-click menu, which makes it a snap to download images or file links as you come across them in Chrome.
For uploading files from your computer to Dropbox, QuickDrop lets you just drag and drop them into an open Chrome window. When you drag a file to Chrome, a box appears in the lower-left corner that instructions you to "Drag files here." Drop a file into the box and it gets uploaded to your upload destination folder.