Overview - One of the brightest spots in Oregon other than Portland, Crater Lake National Park is one of those oddities that makes nature so interesting.
Details - Crater Lake National Park is another National Park that you can do in 1/2 a day or less. Although you can camp here, we do not recommend it, as there just isn't that much to do other than the Rim Drive around the Lake. However, you can take a boat tour down at the bottom of the lake to the island in the center, which will burn through a couple of hours, but we skipped it in favor of simply driving around the lake as we had quite a bit of driving ahead of us (This was the day we drove from Lassen Volcanic through Crater Lake NP through Idaho all the way to Yellowstone, which we don't recommend :) ).
Regardless, you are going to want to go clockwise around the lake, as most of the stops are on your right hand side, making it easier to pull out and take a look. The drive plus stopping to eat lunch took us around 3 hours, but we go pretty quickly, so you will likely want to allow 4, 6-7 if you take the boat ride in to the center of the lake.
Another little stop that most tourists will miss because it is about a 15 minute drive off the main road is an area called The Pinnacles. It is an area of unique rock/lava formations that appear in some ways to be similar to the hoodoos in Bryce National Park. If you go all the way to the end of the road there is a small parking lot and if you head east from there, there is a small overlook about 5 minutes down the road where you can see the formations (below).
Final Words on Crater Lake
Overall Verdict - In our opinion, one of the only things worth seeing in Oregon. Don't worry, its nothing personal Oregon. It's us, not you. Your 55mph speed limits for 300 miles were not at all what upset us. It is entirely logical to go 55mph on an interstate highway. How is your trucking industry doing?
Days/Nights to Camp/Spend Here - 3-7 hours is our recommendation, depending on whether you take the boat ride to the center of the lake or not. We do not recommend camping here, and since we did not, we can't really vouch for any specific campground.
Campground Evaluation - Didn't camp here, so no dice.
Best Time To See Crater Lake - Hate to sound like a broken record, but if you go before 9am, you will not only have the best light, there won't be a soul in sight, making it easier to pull out wherever you like.
Tips/Tricks - Drive the lake clockwise, other wise you will get sick of making left turns very quickly.
Best Hikes - This is an All-American park in the fullest sense of the word, as there are no hikes. You can see the entire park from your car.