The presence on the Internet of both the Mac and the iPhone grew smartly this summer, registering record numbers for each operating system in the Net Applications survey issued overnight Wednesday.

The Mac’s share of Web hits grew 5.34% to a record 8.28% last month, according to the Web metrics firm’s September survey. The iPhone’s share, having surged 57% — from 0.19% to 0.30% — in August (see here), grew another 6.67% to hit 0.32% in September.

These monthly surveys are conducted by sampling browser data from some 160 million visits to websites operated by Net Applications’ clients. Although the company describes the results as “market shares,” Net Applications does not actually measure share of market in the traditional sense of sales revenue or unit sales. It does, however, provide a consistent methodology by which to measure operating system trends.

By this yardstick, Microsoft’s MSFT Windows, while still dominant with a 90.23% share, has been slowly losing ground. Apple’s AAPL operating systems, by contrast, have been gaining share at a fairly brisk pace, albeit from a much smaller base.

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

To get a feel for how Internet use compares with unit sales, check out the chart that Alexis W. Cabot has posted on The Mac Observer’s Apple Finance Board using the latest numbers from Gartner and Net Applications: