It appears that USB 2.0 will be up to 30Mbs and USB 3.0 will be faster (80/60 read write) Those speeds are faster than you will need. Flash memory will not last forever so don't spend too much. I'd would buy the cheapest one and then a higher priced one and see for myself if there is a difference. See below:http://www.newegg.com/Store/SubCategory.aspx?SubCategory=522&name=USB-Flash-Drives
So $15 for an inexpensive one and $40 for a better one. Besides you can always use more storage.