If you have not heard of Greek Ollendorff, it's a great way to reinforce your Greek or to continue learning Greek. It's also in the public domain and hence free. The book has 96 lessons; each lesson has a number of simple Greek sentences as exercises. In the beginning lessons, the "sentences" are simple phrases. As the lessons progress, the sentences become more complex, but not overly complex. The beauty of Greek Ollendorff is that it gives you quality practice with relatively simple sentences.
I've begun recording the lessons, and at the current date I have recorded a bit past lesson 60. I have done the recordings as best I can using the Imperial Koine Greek pronunciation, which I learned from Randall Buth's Living Koine Greek book (you can read my review of it here). I am in the process of putting out the recordings I have done, and I plan to eventually record all 96 lessons. You can subscribe to the Greek Ollendorff Podcast through iTunes or through its RSS feed.
I have put additional information about Greek Ollendorff and the recordings on my blog right here; I definitely appreciate any feedback. I've found that listening to the recordings helps me to internalize Greek as a living language, and I highly recommend it!