Download this to make recordings on a laptop or a desktop. Don't forget to download the LAME encoder as well, or you won't be able to export MP3's. MP3's are your best bet for file size.
The Teaching and Learning Center (in LRNC-208) has a fabulous, super-high quality digital audio recorder available for LSC-CyFair faculty checkout. Check with your campus for something similar at your place if you're not a CyFairian.