OK, so you have installed Ubuntu or another version of GNU/Linux on your Thinkpad and realise that you need to upgrade your BIOS. The files are available on Lenovo’s web site to create a bootable diskette. The problem is that the application is for Windows.
Not to worry. Just download the BIOS update application, extract the diskette image and use it to create an ISO file that you can then burn to a bootable CD.
> wget ftp://ftp.software.ibm.com/pc/pccbbs/mobiles/spsuiv69.exe > cabextract spsuiv69.exe > mkisofs -b IVUJ11US.IMG -o biosboot.iso IVUJ11US.IMG
Then just burn the file biosboot.iso using your favourite ISO burner. Boot from the CD and follow the on-screen instructions.
Please note that, while this worked for me, I take no responsibility for what happens. There is always the risk of BIOS upgrades going wrong, turning the computer into an expensive paper weight.