64 bit processors

[Bruce Dubbs]

Guys,
  How can I tell if I have a 64 bit processor?  dmesg gives:

CPU0: Intel P4/Xeon Extended MCE MSRs (24) available
CPU0: Intel(R) Pentium(R) 4 CPU 3.20GHz stepping 01

/proc/cpuinfo:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Pentium(R) 4 CPU 3.20GHz
stepping        : 1
cpu MHz         : 3193.459
cache size      : 1024 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 1
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 3
wp              : yes

>From what I can tell, some P4 processors are 64-bit and others are not.
  How can I tell if I am 64-bit capable?  I really don't want to remove
the heat sink to look at the processor.

  -- Bruce