I have successfully installed Redhat 7.0 and have had only a few difficulties. Redhat installed right out of box using the built in CDROM drive, however, it will not boot properly. The pcmcia card managaer(cardmgr) locks the machine hard and I need to turn it off and on again to get going. The sound also doesn't work out of box and still isn't fixed in kernel 2.2.17(The ALSA sound drivers get this working). I elaborate on these problems and describe work-arounds, if I know them, below.
PCMCIA does not work out of box. After installing Redhat 7.0 with laptop options enabled, the default behavior is to start pcmcia at boot time, thus causing the system to hang on boot up. To fix this, hit control-x when the graphical boot menu appears. Type linux single at the LILO prompt. Once the machine boots into single user mode you want to remove the SXXpcmcia from /etc/rc.d/rc*.d/ where the XX is some number that I don't recall and the * is a wild card meaning all the directories that match. This allows Redhat to boot. I have no PCMCIA cards and so I haven't tried fixing this. It has been reported, however, that disabling PCMCIA probe(doscan=0 in the pcmcia options file) or loading the USB drivers before PCMCIA fixes the problem.
The machine also has a Lucent based winmodem. Check out Linux Modems for more information. The ltmodem driver is reported to work. I haven't tried it yet. Checkout this site for more information about this driver.
To install X, simply run the Xconfigurator tool by typing Xconfigurator at the prompt when you are root, and choose the SMI Lynx EM+ graphics card option when asked. The i1300 1171 370 has 4 MB of video RAM, some models only have 2 MB. Check the IBM page for details. When asked about a monitor, I just chose the generic LCD at 1024x768 option and all worked fine. Bear in mind that some i Series machines only have 800x600 displays and so you should choose the generic LCD at 800x600 option. The machine will work if you choose a standard 104 key keyboard and PS/2 mouse when asked to specify the keyboard and mouse. The scrolling button behaves as the third button so there is no need for the EmulateThreeButtons option.
After answering all of Xconfigurators questions, you can just run gdm as root from the command line and go on your way. Bear in mind, however, that switching the machine to runlevel 5 to have the machine start X windows on bootup did not work, I didn't pursue this but I think that I hosed something and things should be fine for you. Also, I don't use the startx command so I don't know if it works, but it should.
Here is a copy of my XF86Config file for XFree86 3.3.6. I have a ThinkPad i1300 1171 370 (4MB video RAM, 1024x768 LCD screen). The configuration tool will set up the XFree86 3.3.6 XF86_SVGA server with an appropriate XF86Config file. SMI cards are not yet supported under XFree86 4.0.1.
I have the USB floppy drive and it doesn't just work out of box. You need to manually insert the driver for usb-storage. You can do this as root by typing /sbin/modprobe usb-storage. Then when you plug in the drive it is autodetected as a removable storage device and behaves like a SCSI device. If it is the only USB device on the system then it should be /dev/sda, unless you have a PCMCIA SCSI card that works(If you do tell me how to get PCMCIA working :) ). The floppy can be mounted by typing mount /dev/sda /mnt/floppy as root. If you have an internal floppy(Is this possible?), it should be /dev/fd0 and you won't want to mount /dev/sda on /mnt/floppy. In this case you should just create another mount point like /mnt/usbfloppy.
If anyone knows how to get kerneld to autoload the usb-storage module when needed please let me know. Also, if you have a configuration that seamlessly integrates USB storage devices into the GNOME desktop please contact me. I don't use the floppy enough to do the integration and I can't figure out the kerneld stuff(yet).