For the average everyday guy like me anyhow. Great #1 -Duct Tape. What can I say ? Great#2- Crazy Glue-Fantastic!! Besides the usual repair jobs,Last year I repaired the plastic housing that holds and aligns the gears and shaft for a Genie garage door opener with this stuff. For $2 probly saved $100. Great #3- Caller ID- How many annoying calls do I avoid every day ,priceless. Worst Invention-Text Messaging .We have cell phones and Email ,what do we need this for? Question for teachers,parents and business people. Will this generation be able to compose a business letter someday ?