an easy way for students to practice speaking to the class

Fun get-'em-speaking activity: hand each student two slips of paper, on which they're to write an open-ended question, any question (within the bounds of reason and school appropriateness). Collect the questions, shuffle, and redistribute, checking quickly to make sure each is good before handing out. (By originally giving two per student, you guarantee you'll be able to weed out a few with no real loss.) Sample questions, compliments of my freshfolks:

Why is the sky blue?
Why can't humans fly?
Is fate real?
Gorillas or bears?
If you were robot, would you take over the world?
What's your favorite pet, and why?
Which sport requires the most athleticism?

Then, have students write an answer to someone else's question. Collect the questions again.

Divide students into two teams. Say: "Team One, your question is..." and read a question. Team One sends up a student to answer the question, earning up to six points for speaking fluently (on topic) for sixty seconds.

In later rounds, you can have three students go up at once and use the "three-headed expert" technique, either where each is allowed to give one word as all three combine to answer, or where all have to say the same thing at the same time, watching each others' mouths and listening and struggling to get their minds together, for maximum hilarity.

Even students who are reluctant to speak in front of a whole class will go up in the later rounds, with their peers in tow. Use as practice for a larger, more intense preparation.