I delved into the eye dropper tool yesterday and what a joy! In certain instances, the eye dropper tool is even faster than using style sheets.
I had a two-column text frame with school names, titles and people names. They were varied on each line as to what needed to be bolded.
I bolded one of the words, got the eye dropper and clicked on that bolded word.
The eye dropper changes slightly and gets a small bracket cursor. At this point, I simply held the mouse button down and dragged over words to instantly apply that bolding. And the tool stays in that 'apply mode' until you mouse-click on some other word for new attributes or switch tools.
You can apply the sampled style (font, style, color etc) to a single character, a word, sentence or a whole paragraph.
In this case, since I wasn't using a table, and I didn't have a style sheet for the exact bolding I needed, I just used the eye dropper.
This kept my Style Sheets palette clean with only globally used styles in the list which, when you're doing publications monthly, speeds up applying special style without hunting through a list or memorizing key strokes for seldom used styles.