This is an Alfred Workflow inspired by an @holman's idea:

All todo does is put a file on my Desktop with the filename given. That's it. I aggressively prune my desktop of old tasks and keep one or two on there at a time. Once I've finished a todo, I just delete the file. That's it.

Desktop Todo allows you to create/delete empty items on your desktop from Alfred. That's it.

Open Alfred and type:

t my todo item

will create an empty my todo item file on ~/Desktop.

Adding the -c parameter followed by a color number (see below) will set the 'Label' of the file, just as you can do with the Finder.

t -c2 my important todo item

will create an empty my important todo item file on ~/Desktop labeled in red.

Available colors are:

1. Orange
2. Red
3. Yellow
4. Blue
5. Purple
6. Green
7. Gray

Open Alfred and type d followed by a space will list you empty files without extension (assumed as todo items) from ~/Desktop.

Selecting one and pressing Enter will delete it.