BitBucket - download source as ZIP
For git repositories, to download the latest commit, you can use:
https://bitbucket.org/owner/repository/get/HEAD.zip
For mercurial repositories:
https://bitbucket.org/owner/repository/get/tip.zip
Now Its Updated and very easy to download!
Select your repository from Dashboard or Repository tab.
And then just click on Download tab having icon of download. It will Let you download whole repository in zip format.
For the latest version of Bitbucket (2016+), the download link can be found in the Download menu item.
Pre-2016
First method
In the Overview page of the repo, there is a link to download the project.
Second method
Go to Downloads -> Branches -> Download the branch that you want (as .zip, .gz or .bz2). There you'll find download links for all tags. The links will be in the format:
https://bitbucket.org/owner/repository/get/v0.1.2.tar.gz
By tweaking it a little bit, you can also have access to any revision by changing the tag to the commit hash:
https://bitbucket.org/owner/repository/get/A0B1C2D.tar.gz