I've benefited a lot from these posts, so here is my step-by-step version of Bunanson's and TA-t3's solution for running the Garnet VM on Nokia Internet Tablets (NIT)--aimed at absolute newbies (like me, two months ago)!
[These instructions don't include javispedro's solution for adding SD card support to the GVM--I'll be trying that when I have time too!]

Acknowledgements:
Here are links to previous posts that helped me a lot!

http://www.internettablettalk.com/fo...9&postcount=10
http://www.internettablettalk.com/fo...0&postcount=12
http://www.internettablettalk.com/fo...ad.php?t=15518
http://www.internettablettalk.com/fo...ad.php?t=12297

1. Requirements:
-Latest version of the Garnet Virtual Machine (GVM) from ACCESS
-NIT running Diablo--i.e., latest version of Maemo OS
-Script-friendly text editor such as Leafpad, vim. I've also used TextWrangler (Mac OSX).
-a way of gaining root access to your NIT. See this link for instructions: http://wiki.maemo.org/Root_access

1a. Recommended:
-Filez.prc Palm freeware. This program allows you to see your HotSync ID in the GVM as well as Device serial numbers, application Creator Codes and other useful information.
-a linux-friendly file manager (the included Maemo File Manager is not sufficient) such as emelfm2 or Midnight Commander. You can find these downloads by doing an internet search for "Maemo emelfm2" or "Maemo Midnight Commander". Install one of these applications to your NIT using the Application Manager. emelfm2 is more graphically pleasing, but Midnight Commander's menu options use English rather than the rather cryptic icons found in emelfm2.

2. Open up the Garnet VM. This will execute the Garnet VM Launcher (which is a separate program from the actual GVM). Within the GVM Launcher, you can decide on settings for your Garnet Virtual Machine which then creates a file called gvm.store where your actual Palm apps will be located.
There are some programs pre-installed--the PIM apps and Prefs. These apps use OLD Palm PIM app formats (i.e., OLDER--thanks TA-t3!--than Palm T3 and earlier) so they will not be able to read the PIM database files from your newer Palm devices. You will have to do a HotSync or convert your database files to the old format if you want that data on your GVM.
You need to hit the Settings button to create your new gvm.store file. Choose:
-Storage heap size--you can choose sizes from: 1 MB, 2 MB, 4 MB, 8 MB, 16 MB, 32 MB and 64 MB. I would recommend a larger size. The easiest way to wipe out your entire GVM installation is to accidentally exceed the storage heap size while the GVM is running by, for example, installing too many files or using up too much memory in the Palm environment.
-Then, hit the "Reformat storage" button to create the gvm.store file.
-The other settings can be changed later if you wish.
-Hit the "Save" button.

You can now change some of the settings for individual apps in the Launcher. For example, you can choose the Calc app and hit the "Configure" button and then increase the Dynamic heap size up to 4 MB. You can also change the Device model and Display compatibility, but these are mostly important for certain Palm apps that run better on certain device models.

Recommended, but optional, is to install Filez. To do this, just hit the "Install" button and follow the instructions to install the Filez.prc. Some have recommended the following procedure to speed up the install process (useful, especially if you have multiple apps to install):

-Choose one of the Palm apps
-Hit the Launch button
-After the GVM starts, hit the Home button on your NIT and go back to the GVM Launcher screen
-While the Palm app is running in the background, use the GVM Launcher "Install" button to install applications.

I have found this procedure to be considerably faster than NOT having the GVM running in the background, but I choose not to do it because:
-I've often forgotten that the GVM is running and I've tried launching one of the newly-installed apps to see how it runs. When you try to run more than one instance of the GVM at one time, you will cause a crash which can wipe out your entire installation and set you back to square one.
-When using this procedure, I've had the GVM Launcher crash on me a few times after installing half a dozen apps in a row.

When you're done setting up a "basic" gvm.store--in other words, one which includes the essential apps you want to see in EACH of your gvm.stores--assuming you want to run multiple ones--then, exit the GVM Launcher.

[Why run multiple gvm.store files? The main reason is the 64 MB Storage heap limit. On my old Palm TX, I was using almost all of the 128 MB of RAM even with almost all of the data files on the SD Card--and running Dmitry's excellent SDHC Driver! If you want enough room to hold a large amount of Palm apps/data, you may need multiple gvm.store files. The other reason is speed. The more apps you have in a gvm.store file, the slower the startup will be. If you have separate gvm.store files for your essential apps, they will launch faster. Finally, the other issue is crash prevention. My multiple gvm.store file storage heaps are all set at 64 MB. To prevent the storage heap violation error, I try to leave at least 20 MB of free storage "buffer" in each gvm.store. Of course, with the new GVM SD card hack, this will not be as much of a problem].

To be continued...