Online video usage in the U.S. is up considerably from the same time last year as time spent viewing video on PC/Mac/laptops from home and work locations increased by 45%.

Along with its listing of the top brands and companies on the web for June 2010, The Nielsen Company also found that the average time spent online in the U.S. grew more than three percent compared to the previous month.

More than 10 billion videos were streamed in the U.S. in June 2010, a 1.3% increase over the number of streams last year and nearly a 4% jump over last month’s figures.

The number of unique viewers of online video increased 1.6% year-over-year, from 133.7 million unique viewers in May 2009 to 135.9 million in May 2010.

In April 2010, more than 133 million unique viewers streamed 9.4 billion videos in the U.S.

For March 2010, the number of unique viewers of online video increased 1.3% year-over-year, from 130.1 million unique viewers in March 2009 to 131.7 million in March 2010.

Whether watching a short clip on YouTube or an entire TV program, almost three-quarters (72%) of Internet users view videos online — amounting to 144 million people.

The number of unique viewers of online video increased 10.5% year-over-year, according to The Nielsen Company, from 127.6 million unique viewers in February 2009 to 141 million in February 2010.

The number of unique viewers of online video increased 5.2% year-over-year according to The Nielsen Company, from 137.4 million unique viewers in January 2009 to 142.7 million in January 2010.

The Nielsen Company today reported overall online video usage and top online brands ranked by video streams for December 2009. Year-over-year, unique viewers, total streams, streams per viewer and time per viewer were up, led by 13 percent growths in time per viewer.