When working with images I sooner or later usually run into the problem of creating thumbnails. Resampling images is not really difficult in the major programming languages however I have not found built-in support for caclulating thumbnail dimensions neither in .NET nor in PHP. And it seems that this made me re-invent the wheel over and over again creating codes with various lengths just for this simple task.
In Sense/Net 6.0, the open source ECMS I am working on I came across the exact same problem: I wanted to resize images, this time on the fly. This time however I decided to do it a bit less complicated as in previous cases and create a clean and simple solution. After a good deal of googling, tutorial reading and planning I came up with a fairly simple and good code snipplet.