Siege: http://www.joedog.org/JoeDog/Siege

Baseline Benchmark Wordpress-svn PHP-5.3.15-dev Apache-2.2.22 prefork
~> siege -c 5 -b -t30s "http://wp1.localhost/?p=1"
** SIEGE 2.70
** Preparing 5 concurrent users for battle.
The server is now under siege...
Lifting the server siege..      done.
Transactions:		         579 hits
Availability:		      100.00 %
Elapsed time:		       29.41 secs
Data transferred:	        4.68 MB
Response time:		        0.25 secs
Transaction rate:	       19.69 trans/sec
Throughput:		        0.16 MB/sec
Concurrency:		        4.98
Successful transactions:         579
Failed transactions:	           0
Longest transaction:	        0.51
Shortest transaction:	        0.14