Do any of you carry a stopwatch with you on the court for possible timing corrections or other reasons?

No, I don't work games with a monitor or under a rule set which allows me to correct timing mistakes with a stopwatch.

In NCAA-Men's, the table is required to have a digital stopwatch at the table.

I don't carry anything onto the court with me but cough drops and a spare whistle (and I don't use it for AP situations), whether I'm working HS or college.

*naw, that is wayy too much work, I just rely on my memory and consult the table for verifications.

Same in NCAAW. Used to time TOs and injury intervals. Not strictly enforced at D-3 and NAIA levels (some times the scoreboard is used, sometimes we just count -- especially for the injury and DQ player intervals; sometimes it's the second hand on a watch).

Haven't used a lanyard 20 years. Cost's me a few games now and then, because some people believe I am just doing it to be different. Not making $$$ money doing this anyway. Molten has a whistle called the Dolfin that is the best whistle I have ever used.