My n900's display/touch screen is completely inoperable and I am unable to get even the USB working. So USB, bluetooth and commandline are all out.

Is there a button I can press to hard reset it or some hardware I can take out to get rid of the personal data?

If not what is the best way to physically destroy the phone? I don't have a firearm or any special equipment. Should I just dunk it in water and run it over with a car a few times? Then I can distribute the small parts among 8-10 different spots/dumpsters/water bodies.

No such button. [edit]That I know of at least.[/edit]

If you're that determined to destroy it (I can understand this), then yes, soaking it in water, then smashing in with a hammer (probably way more efficient than driving a car over it) should make it perfectly inoperable.

I suggest you disassemble the device and perform the above on just the motherboard - the keyboard, screen parts, perhaps just the frame in general, definitely the battery, are all things that may well be useful to someone in the community, and certainly have no useful data from the phone on/in them.

You might be able to use the video out to hook up a tv.
If you have no security pin set and rootsh installed then that may be a more secure way:
Turn on device
Ctrl Shift and X to bring up terminal
(credit to Hurrian here)

if you want to destroy it physically then smash it with a hammer. this is the most secure way. can you put it on ground and run it over with a car and create a video and upload it to Youtube. i want to see what will happen to N900 as i never found such videos on Youtube.

You can still vnc or ssh to it and use it as media and/or webserver. it's still got a life even as such, no need to destroy it.

However replacing the digitizer is trivial and usb can be done without if you still would like to use it.

Please don't destroy it physically!
It has replacement parts to another people. Can you solder out from motherboard eMMC where is all your data?

I think you find people that help you in this thread: http://talk.maemo.org/showthread.php?t=73579
And maybe they want buy your phone for testing after solder out.

Why don't you ask Mr. Vercetti to do it?
[I love GTA VC ]

Running over with car probably won't destroy the chips that hold your data. Neither will water.

If you're that paranoid, disassemble the phone, remove the nand chip(s) and smash them with hammer or burn with torch.

Then sell leftover parts, or donate to community, or keep as spares for your next n900

I will give the TV out thing a shot. Thanks very much.

Next n900? Lol, love that. Definitely tempted to just get another one but the $20 nokia monochrome phone I'm using is pretty good at calls and txts. It runs for an entire week without charging the battery. I love it. If I feel like throwing out several hundred (or here India about a thousand) $$$ I'll probably get the BB Q10 next (no offense!)

Why not set the eMMC on fire?
Or the whole phone