In Illustrator dialogues you can move items via numerical values. The cool thing is you can use different systems, you can enter values like 12 pt + 2 mm. Illustrator automatically does the math and performs the value change.
This makes working with numeric values very easy. If someone tells you add another 2 cm, you simply type 2 cm and Illustrator will translate it into say points and execute the change.
I am actually using this Illustrator feature to try out my new MacJournal. Years ago I played around with it. Now I bought it in one of those Mac-update Bundles. It great you can send entries directly from MacJournal to your blog. This is super helpful. I am constantly taking notes and I must admit Mac-Journal is very good at assisting me. You can simply drag stuff onto it to create entries, you can careered sound and video. I am glad I bought it.