$ time (for i in `seq 1 100`; do perl -MJSON -e1; done)

real	0m2.635s
user	0m1.930s
sys	0m0.510s

$ time (for i in `seq 1 100`; do perl -MJSON -MLWP::UserAgent -e1; done)

real	0m7.111s
user	0m6.060s
sys	0m0.740s