The numbers are still in flux, but preliminary figures released Sunday morning by Net Applications show Apple’s AAPL Internet market share dropping a couple percent in February.

One chart shows Mac OS X with a 9.61% share, down from 9.93% in January. Another puts the share at 9.71%, down 2.22% for the month. The latter seems consistent with other data in the report and is likely to withstand review.

In a separate report, the Web metrics company took its first detailed look at mobile Web browsing and found the iPhone with a “commanding lead” over its such rival systems as Windows Mobile and Google’s GOOG Android. As Net Applications measured it — a big caveat, it turns out — 66.61% of mobile Web searches in February were made from iPhones. See here.

In the broader search market, Microsoft MSFT Windows in its several versions continues to dominate Web traffic with a 88.42% share (or 89.37%, depending which chart you believe), up a smidgen from January. Among the also-rans, Linux was up more than 6% for the month, to 0.88%.

Net Applications’ monthly surveys are conducted by sampling browser data from some 160 million visits to websites operated by the firm’s clients. The company describes the results as “market shares,” but they do not actually measure share of market in the traditional sense of revenue or unit sales. They do, however, provide a consistent methodology by which to gauge operating system trends. (See Ars Technica for a good review of the different ways to measure Mac market share.)

To see Net Applications’ March 1 report, click here. The results are summarized in the table below.