Finding similarity between LASER for golf clubs and golf balls and LASERSWING for golf practice devices, and noting that "the term ‘swing’ is both common and descriptive" and therefore "may be given little weight in reaching a conclusion on likelihood of confusion"
Holding that purchaser confusion is the "primary focus" and, in case of goods and services that are sold, "the inquiry generally will turn on whether actual or potential `purchasers' are confused"