Yes, running the latest version on your lappie is good when it comes to power management. Your success may depend on whether you use APM or ACPI as your method.
With the recent kernel 2.6.8 and on, ACPI is probably the preferred method. However, for best result you may have to recompile your kernel and applying an ACPI patch
. Check these forums and Google on how to recompile kernels if you've never done it.
Also, ACPI may require you to some other tricks in order to get your laptop to resume successfully (often involving graphics and USB). Since you have a ThinkPad you really, really want to search the archives of, and probably join, the Linkux-ThinkPad mailinglist
. I can assure you that you are not the only person running Linux on a ThinkPad...
/TLV (using Debian on a R40 with successful suspend/resume ACPI)