Regarding your question about "OTC", this stands for "over the counter". Both Pink Sheet stocks and OTC BB stocks are sold "over the counter", ie, not on an exchange.
CPOW is a pink sheet only. Some of these sites list a CPOW.OB and a CPOW.PK. One of those sites is Google Finance and it can be confusing. Look again and you will see CPOW.OB is graphed only to 1 Sept 2010. This is because in the reverse merger with General Bio Energy CPOW moved from the OTC to the Pinks. CPOW.PK is the graph you want and is the ONLY report for this company at this time.
It's a little confusing but for whatever reason, every stock on the RegSHO list has an "O" in the last column for OTC even though some of them are Pinks. Who knows why.
You can do a Control-F and search for CPOW or any stock you want to see how many shorts there were. As you can see, nearly 50% of Friday's trading was short volume.