How to delete an edit in Final Cut Pro (un-blade) I want to be able to "undo" the blade tool, in effect merging clips
  together. How can I do this?


(Answered another question without noticing it was for Final Cut X, not FCP 7, but here is the answer for anyone using Final Cut Pro 7)
If you have made an edit and you want to remove it, you can click on the edit then press delete and the edit will be removed. 

fig1. selected edit:



Note that this only works if the time on either side of the edit hasnt changed, as indicated by the red triangles. If you have cut out any video, you cant delete the edit: