Here is a collection of projects ideas and minimal designs that I have yet had a chance to develop into a full design / project, or haven't been able to due to a lack of resources (it sometimes take months to find the right part at the right price from eBay).
10Kw Dual Resonance Solid State Tesla Coil (DRSSTC):
A while back I found 2 1200V 600A IGBTs on eBay for a awesomely cheap price of $100 (they sell for $2000 new, each). Knowing their value, I purchased the pair and placed them away in deep storage for a future project. The future project was determined to be a massive solid state Tesla Coil. I mostly have placed this design on the back burner because of the sheer cost of parts. I'm waiting till I can eBay most of the more expensive parts at a reasonable price and then expand upon that once I have acquired most of the main components. Furthermore, I hope be able to use Tesla Coils as a research opportunity in college. Tesla Coils can in theory have a lot of practical uses and there is currently not much research into the practicably of DRSSTCs.