I would tend to agree with avoiding "educational" products. However, getting a decent microscope, especially a USB one so you have your computer screen to look at instead of the tiny little eyepiece, is WAY cooler than a magnifying glass.

If you want to assemble a portable "field science" kit, I definitely agree:

Magnifying glass
Binoculars
A nice, bound, notebook with good pens
A butterfly net
Bird/insect identification book
Star chart
Good science coaching (that's where you come in)

Even better than TVs are computers! USB microscopes are pretty awesome, and laptops, unlike TVs, are portable. Plus, you can do more with the video once it's on a computer. Something like this: http://www.amazon.com/Digital-USB-Microscope-Video-Camera/dp/B0011E0IYW

If you get a telescope for them, be sure to make it a decent reflector. One of the biggest ways people go wrong getting into stargazing is by getting a cheap telescope that is worse than a pair of binoculars. Not only is the result blurry, but you can't get enough light to see the fainter objects that are the most interesting. Contact your local astronomical society for a good deal on a used scope. You might even be able to get a mount for a digital camera so your kids can photograph what they see and send it to relatives or post online. A photo they take of the moon or Jupiter will really make them smile and be encouraged. If you get REALLY into it, you can check out some of the amateur research requests on AAVSO. :) But little steps at first.