I usually carry a back day pack w/water, jacket, etc. I'm concerned if that's smart. A friend of mine in MA had someone try to slash open her backpack in the park. Any suggestions? How do you carry your "stuff," or don't you?

Small backpacks and daypacks are pretty common. I haven't heard of this happening; I don't think it's all that common. The usual warnings are not to leave anything unattended or in your car.

A side note: If you spend any time at Playa Manuel Antonio, keep an eye on your backpack while it's on the ground. During my visit there, I saw raccoons/monkeys digging into bags and backpacks all day long, taking food.

The park typically has many people so getting confronted within the park itself probably wouldn't be that common. The majority of people are with guides and you move through the park as a small group. If you are just out for a walk within the park, you might have a little different experience - especially if it is very early, just before dark or if you are spending time on the beach.

We saw many people with big backpacks but I think some would have been happier with less stuff. We took a few sips from our water, used our camera and didn't have any use for the jackets we brought. Each visit would be different, but unless you are having a picnic on the beach (guides usually give you about 10 minutes there), you proabably don't want to bring a lot of things with you. Our trip took a couple of hours and everyone enjoyed fruit/drinks as soon as we finished so I can't imagine needing to bring a lot of food. We also spent time at a small store before we left so those who missed breakfast or lunch could grab a bite to eat. A fanny pack or camera bag might be all you need. On the way back, we walked down a steep, muddy little path plus crossed over water so packing limited items made it easier going.

Pacsafe do a really secure day pack that I have been thinking of getting-
http://www.pacsafe.com/www/index.php...tail&id=22

I have a pacsafe day pack that I really like. It is slash resistant and has several features that help make it secure. I usually leave out the inner locking bag because it is so heavy, but often use it to secure a laptop in when I am traveling. Anyway I think its a good product, but expensive.

I saw some good prices on different pacsafe products recently at www.campmor.com .

Yes I bought mine on-line by searching around and paid less that what pacsafe shows.

I also have a pacsafe bag I used in CR this past year. Really like it. It has reinforced steel mesh in the straps and bag so that, even someone tries to cut it, it won't cut.