If I had 50,000 SP for a week one thing I would do is power up my account as much as possible so I could continue helping the wonder content creators here on steemit. Speaking of content creators, I would use it to support as many of the artists, writers, photographers, and developers here on steemit. I would also go through the introduceyourself tag every day and look for good minnows new to steemit that could use a substantial boost to their earnings in their first week.
The #introduceyourself tag is a good idea! Steem on!