Allen McGuire talks about SSMSBoost:
Tip 4: Results Grid aggregates – Some people do a lot of calculations with their data, whether it’s sales data or whatever. You end up saving the query results to Excel and about five minutes later you have the totals, etc. With SSMSBoost, you can have your totals in seconds. Below I’m selecting 10 records from a sales related table. Say I want to get the SUM, MIN, MAX and Count of the SALEPRICE. All I do is slide my mouse down the column highlighting the cells and a pop-up will appear with that information:
This is probably my second-favorite feature of SSMSBoost; my favorite is automated crash recovery, and my third-favorite its snippet support. SSMSBoost has a free version and I use it myself. I try not to push many tools here on Curated SQL, but this is one worth checking out.