Whether it's your grandchild's dance recital or Little League game or the latest adorable cat video, chances are you've watched something on YouTube.

The Internet site has evolved from being exclusively a place for amateur videos. Hundreds of "channels" of videos from professional filmmakers can be viewed, although the website's old slogan, "Broadcast Yourself," still applies.

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To learn more about YouTube -- and how to broadcast yourself -- Sachem Public Library is having a free seminar, presented by SeniorNet, on Wednesday at 3:30 p.m.

As for SeniorNet, this has been its best year ever in helping Long Islanders learn about technology. More than 1,000 adults have attended SeniorNet seminars this year, a record for the not-for-profit volunteer group that is primarily focused on adults 50 and older. For more information on its free seminars or low-cost computer training, call 631-427-3700, ext. 268, or go to seniornetli.org.