SharePoint Solution Exporter
if you are needs to download SharePoint Solution, you can use SharePoint solution exporter. This tool shared on codeplex and you can download http://solutionexporter.codeplex.com/ link. By default Sharepoint don't allow download your solutions on central admin.
This section has only two options one of them Deploy Solution and the other one is Romove Solution. One day I lost my solution instalation setup and wsp file and I need to deploy same solution the other farm. This tool was very usefull for me. Download this application source code codeplex or my site and run application your Sharepoint enviroment. Application load your web application list and wait your selection wich application solution(s) you want to download or global deployed applications.
Click wich solution you want download and click Save as button. Application ask you a destination directory. Select ona and click okey.
Finaly application save your solution which you lost setup or wsp, download your destination directory.
SpSolutionExporter.zip (83,68 kb) you can download this link.