Although these modules are not IBM originals they are guaranteed to be 100% compatible with your thinkpad and meet or exceed the specifications from the manufacturer.
IBM PART# 10K0034 Comaptible 1GB PC2100 DDR SO-DIMM
$120.00
IBM PART# 31P9834 Compatible 1GB PC2700 DDR SO-DIMM
$125.00
IBM PART# 10K0032 Compatible 512MB PC2100 DDR SO-DIMM
$55.00
IBM PART# 31P9832 Compatible 512MB PC2700 DDR SO-DIMM
$54.00
IBM PART# 10K0030 Compatible 256MB PC2100 DDR SO-DIMM
$27.00
IBM PART# 31P9830 Compatible 256MB PC2700 DDR SO-DIMM
$28.00
IBM PART# 10K0028 Compatible 128MB PC2100 DDR SO-DIMM
$15.00
IBM PART# 31P9828 Compatible 128MB PC2700 DDR SO-DIMM
$16.00
IBM PART# 73P3840 Compatible 512MB PC2-4200 DDR2 SO-DIMM
$49.00
IBM PART# 73P3844 Compatible 1GB PC2-4200 DDR2 SO-DIMM
$98.00