I wanted to confirm some Cisco serial numbers as the product stickers were damaged, I found this command that gives you this information (as well as a lot more)

  sh ver (show version)

This gives an output similar to below:

Cisco IOS Software, C3560 Software (C3560-IPSERVICES-M), Version 12.2(35)SE5, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Thu 19-Jul-07 18:15 by nachen
Image text-base: 0x00003000, data-base: 0x01300000

ROM: Bootstrap program is C3560 boot loader
BOOTLDR: C3560 Boot Loader (C3560-HBOOT-M) Version 12.2(25r)SEE4, RELEASE SOFTWARE (fc1)

Switch uptime is 27 minutes
System returned to ROM by power-on
System image file is "flash:c3560-ipservices-mz.122-35.SE5/c3560-ipservices-mz.122-35.SE5.bin"

cisco WS-C3560G-24TS (PowerPC405) processor (revision D0) with 122880K/8184K bytes of memory.
Processor board ID FOC1237W3P4
Last reset from power-on
9 Virtual Ethernet interfaces
28 Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address       : 00:24:13:D6:AE:80
Motherboard assembly number     : 73-10215-04
Power supply part number        : 341-0098-02
Motherboard serial number       : FOC12481D4P
Power supply serial number      : DCA124591XA
Model revision number           : D0
Motherboard revision number     : C0
Model number                    : WS-C3560G-24TS-E
System serial number            : FOC1237W3P4
Top Assembly Part Number        : 800-26851-01
Top Assembly Revision Number    : C0
Version ID                      : V03
CLEI Code Number                : COMW400ARC
Hardware Board Revision Number  : 0x09


Switch   Ports  Model              SW Version              SW Image
------   -----  -----              ----------              ----------
*    1   28     WS-C3560G-24TS     12.2(35)SE5             C3560-IPSERVICES-M


Configuration register is 0xF