PROCESSOR REPLACEMENT If you wish to learn how to replace the CPU, get the service manual and see page 163 (5.19) for instructions on how to do so.
Battery life was a big concern to me. As is, the v2110 could run 2h on max settings (max brightness, WIFI enabled), and a little more than 2h30 with the screen dimmed and WIFI off. This was obviously right for the price I paid. But I knew the Celeron-M could be replaced by a Pentium-M, not only for better performance, but also for better battery life, since the Celeron-M DOES NOT support any kind of speedstep. The only type of supported processor in this computer is a DOTHAN chip with 400fsb and 2mb of L2 cache. This can be found on eBay. BANIAS type does not work at all (this is the first generation of Pentium-M). SONOMA type works (third generation of Pentium-M), but at a slower speed (400fsb instead of 533fsb). I've tried all three types. (Note that one user reporter that this V2000CTO had a 915 chipset, which supports the newer 533FSB. Check in device manager before attempting!) When I proceeded to replace the processor, I couldn't notice an increase in speed, but battery life jumped to an easy 3h with everything on (max brightness and WIFI on) and a big 4h30 with screen dimmed and WIFI off. Knowing you can find this processor for about 60$ US used on eBay, this is kind of an improvement.
I snapped a deal directly with HP for the 12-cell battery. Runtime literally doubled; with WIFI enabled, screen at maximum setting, I can last 6h30 with lights tasks. With WIFI disabled and screen dimmed, it is possible to last 9h!
RAM UPGRADE If you wish to learn how to upgrade the memory, get the service manual and see page 121 (5.6) for instructions on how to do so.
There was no problem in recognizing the ram, the chipset is known to support up to 2GB, so this should not be a concern for most of us. The motherboard initially has DDR-333, but should also take DDR-400 at DDR-333 speeds at worst. I didn't try DDR-400, sorry.
OPTICAL DRIVE REPLACEMENT If you wish to learn how to replace the optical drive, get the service manual and see page 127 (5.8) for instructions on how to do so.
The DVD drive can be replaced; mostly any kind of drive will work, but be careful choosing the drive, as the FACEPLATE might not be right. I have tried a couple of drives, most of them didn't have the LED (for activity on the DVD)or the eject button at the right place. For those who didn't know, V1xxx, V2xxx, DV1xxx, DV4xxx all share more-or-less the same component. I found out that the DVD burner of the DV4000 worked quite well with the position of the LED and the eject button. The drive was recognized immediately. Same goes for the hard drive, but this one is easy, you can buy one at your local computer store, so this is not a big achievement for me. The faceplate of the DVD drive "clicks" if you put your hands on it, and put some force to lift the laptop. Just by looking at it, most of the force is put on the DVD drive instead of being put on the casing of the laptop, probably causing unnecessary force on the DVD drive and/or connector. I found that you could fix that yourself by removing the exceeding plastic on the faceplate of the DVD with some sandpaper.
HARD DRIVE UPGRADE If you wish to learn how to replace the hard drive, get the service manual and see page 117 (5.4) for instructions on how to do so.
I initially changed the 40 GB 4200 rpm drive for a bigger 100 GB 4200 rpm. But after seeing that I was not using more than 50gb most of the time (generally less than 40gb when I don't have ISOs and DVDs hanging around on the hard drive), I opted for a much faster and smaller drive, the Hitachi 7k100 60GB, which is a 7200rpm drive. I saw my average read speed jump from 24,5mb/sec to 32,5mb/sec, and access time from 20msec to 15msec. I was able to get a nice sale price for the 100 GB, so much that I didn't need to spend more than 20$ to get the faster drive. That's a nice trade!
KEYBOARD FIX If you wish to learn how to remove the keyboard, get the service manual and see page 135 (5.10) for instructions on how to do so.
The keyboard is good, but most V2xxx keyboard I've tried shared the same problem; when typing in the area where the arrows are, you can feel that there is space between the keyboard and the metal casing. You can hear a vibrating sound, like if the keys were bouncing. The easy fix is to remove the keyboard, and put some kind of thin cloth, kleenex, whatever below the keyboard. The keyboard now becomes firm and easy to use. See a picture of the fix.