IP Networking

I'm running a Windows application under Wine that is accessing the internet, and I would like to capture and log some or all of it's activity.

That is, suppose it is retrieving this:
http://example.com/some.php?user=ken&address=mainstreet..
It's sending data in the request, potentially personal data.

I want to know what it's up to.

I guess I could use strace, but that would generate an enormous amount of data.
Is there any way I can capture just the HTTP traffic?

You might filter strace output real time, using options like -e to keep the load down.

You might install a firewall and set it to log packets.

You might install a web proxy so you can monitor all browsing. HTTP can occur on ports other than 80, so filtering outside a proxy is a bit difficult, as you have to detect and store state on every tcp connection that is started, to see if it turns out to be HTTP, and if not, discard that connection, and if so, remember it until it is finished and include that connection's packets.

You can also use tcpdump, or a full-blown graphical network monitor like wireshark(which, incidentally, can read tcpdump files.)