Android :: Simultaneous Http Requests

Is there a limit on the number of simultaneous http requests of the form:

HttpResponse response = client.execute(request);

I'm interested in any official limit as well as practical ones.

(In a previous life, you had to dig deep to discover that WinMo only allowed three WebRequests to be open at a time.)

Let's say I have a list of 20 files to download on a background thread.

Should I: Download them one at a time, blocking the thread (but not the UI thread) to wait for each one? Start 20 threads each downloading one of the files?

I expect the answer may be somewhere in between, where I create C threads and work on the queue of N files, where C is a number like 3 or 4.

I suspect some of you here have already done some experimentation and know the magic number. In addition, I suspect there may be more efficient ways of doing what I'm doing than creating a new DefaultHttpClient for each request.