The May market share figures for U.S. Internet search are out from Nielsen//NetRatings today. Here's the one-page PDF with all the figures.

Google maintained its commanding lead with more than 4 billion searches, up 44.9 percent from a year ago, and good for 56.3 percent of the market.

Yahoo had more than 1.5 billion searches, up 18.6 percent from last year, and held 21.5 percent of the market.

Microsoft's MSN/Windows Live Search, rounding out the top three, had 605 million searches, only 0.8 percent, and representing 8.4 percent of the U.S. market.

Rounding out the top 5: AOL, which grew 5.1 percent and held 5.3 percent of the market and Ask.com, which saw searches decrease 2.8 percent since last May and had a 2 percent share of the market.