I will like to make this contribution @makerhacks

Acually raspberry post on steemit is very rare, i will say yours is the second, will love to see more post about raspberry but how can this be solved?

What are the best ways to track entries and judge?

I will say tracking entries is something that might not be a easy one but the best two ways that can be easy is to create a particular tag which they will make use of, and they can also drop their post link under your particular post. I think that will be easy enough. To judge may be some how hard, but the best way is to get someone who have ideas about raspberry, making use of bot to choose winner will make it look somehow and not interesting because it might choose post which may not be in line.

How can we make it fun?

How can it be fun, i think the best way is to make it as simple as you can imagine. When it is too hard to people to solve or participate in, it will drive them away.

Can we do this on a regular basis?

Doing this on regular basis may take lot of giveaway but on regular basis will be a good idea and it will give the minnow to have more chance to participate in it.