Harold - One like that would make me buy another loco.

1- Whenever we travel, I always take my book which lists all the train museums.
I usually make a point of visiting whatever neat train places and old military forts that happen to be along our route of travel.
Before we leave, I go through through the train guide and highlight places that are within reach (an hour or two) of our general route of travel.
2- Frequency - 2 to 20 a year. Depends on where we travel.
3-No
4- I've been to so many neat train places, it would be hard to pick a favorite. Those with pre-1900 stuff are my favorites, whether it's big or small.
Some of the more  memorable ones for me were in Sacremento CA, San Diego CA, Golden CO, Durango CO, Omaha NE, East Ely NV, Carson City NV, Ogden UT, Baltimore MD, Council Bluffs IA, Kennesaw GA, Strasburg PA, Scranton PA.
5- Pre-1900 mostly, wild-Westy feel.
Advertise - blow the whistle every few hours

Me too. I can't understand why some people are so worried about how many posts they've made.
All it takes is a pencil and paper to make a mark every time you post on here. Then you will know.

Kyle -
You also have to be careful with what you post and that you are not infringing on copyrights, trademarks, etc.  Especially if you charging a fee.

You could try this book for ideas - 101 Track plans... by Linn Westcott
http://www.trainplayer.com/Site2/101%20Track%20Plans.html
or this site - Thor's Trains
http://www.thortrains.net/

Sheldon,
I'm on my 4th Astro/Safari minivan and I love them. It really bums me out that they were discontinued. I never did like the Ford/Moper ones.
My Safari has ample headroom for a tall guy like me where most other vehicles don't.
I can haul 4x8 sheets of anything (train layout) without fear of them getting wet and without having to buy a pick up truck to do it.
I can spread out the sleeping bags and sleep in my van because there is enough room for a tall guy like me to stretch out. It good when we are traveling and come to somewhere where the motels are full.
It's small enough to get into multi-level parking garages which I couldn't do with full size vans.
It's all wheel drive, so I can traverse mountains and gullys. It helps when you are exploring abandoned railroad roadbeds.
I get about 18 mpg when I'm traveling so I can live with that. It's my all purpose vehicle to me.

Depending on how permanent you want it, double sided tape would work.

I am only offering my thoughts and can't remember if I read this somewhere.
The British use railway and we (the US)  use railroad.  Very early ones in the US used railway because of the obvious British connections back then. As we became more Americanized, we used railroad.

I said it on the old board but I'll repost it here.
A good way to get ideas for layouts is EBay.
There are often quite a few for sale on there and I enjoy looking at other people's layouts to get ideas.
I use the following search parameters -
In MODEL RAILROAD, TRAINS - "layout -pallets -crates -oil -loads -hay -barrels -garden -freight -barrel -skull"

http://toys.search.ebay.com/layout-pallets-crates-oil-loads-hay-barrels-garden-freight-barrel-skull_Model-RR-Trains_W0QQcatrefZC6QQcoactionZcompareQQcoentrypageZsearchQQcombineZyQQcopagenumZ1QQfcdZ1QQfposZ63601QQfromZR10QQfromZR9QQfrppZ100QQfsooZ2QQfsopZ2QQsaatcZ1QQsacatZ479QQsatitleZlayoutQ20Q2dpalletsQ20Q2dcratesQ20Q2doilQ20Q2dloadsQ20Q2dhayQ20Q2dbarrelsQ20Q2dgardenQ20Q2dfreightQ20Q2dbarrelQ20Q2dskullQQsotrZ2QQsspagenameZSTRKQ3aMEFSRCHQ3aSRCH

I use that to avoid people just selling barrels and stuff under "layouts".

Sometimes, I just put a drop of Bachmann's conductive lube on a joint where I'm having a problem with a joiner.
I do this rather than risk messing up a piece of EZ Track by trying to get the old joiner off.

What about the weight of the sand?
An open hopper full of sand in a rainstorm could get really heavy.
Would the open hoppers be able to handle the weight?

Andy,
How big is your layout?
Do you have room to expand inside/outside the ovals?
Is your track secured to the layout or can you rearrange it? Maybe a folded dogbone or an over and under?
Instead of just ovals, can you rearrange it something like the WGH configuration?
A few more turnouts will allow you to experiment a little.
Hamish's ideas are good.

I have some here but there aren't any #5 tunrouts.
http://www.sarget.com/trains/traintips/bach/traintip-eztrack.html

Check the internet. There are dozens of sites.
Google - "model railroad scenery"

My favorites would be pre-1900 steam.
What are diesels other than different colored boxes with the only visible moving parts being rolling wheels?