tcp conversation with time stamps?

I am trying to analyse the performance of a web based
user interface (JSP, if you care...)

I have succesfully captured a session's packets
to a file, using tcpdump.

Viewing the packets in ethereal is impresive,
but confusing(since I'm not a network guru).

Ethereal's "analyze->Follow TCP Stream" gives
me an almost perfect dump, which corresponds
to my (application level) understanding of
the communication between client/server.

Lovely.

But sadly, from my performance analysis requirment
the one thing missing from "follow TCP stream"
is timestamps.

So; can anyone tell how to either merge/add timestamps
to the ethereal output or recommend some other tool
that will generate a "tcp stream" with timestamps?

BugBear