We'll wager you didn't know Macworld was going on today, did you? Pathetic jokes aside, Western Digital has lined up a pair of launches today in San Francisco to coincide with Apple's final Macworld keynote, as we're treated to the My Passport for Mac portable HDD and the My Book Mac Edition. Truthfully, the only real difference between these drives and their vanilla counterparts is the pre-format process; with these, they both come "pre-formatted for Mac," saving you the tiresome task of converting 'em to HFS+ Journaled yourself. Additionally, these USB 2.0 drives are made to work "seamlessly" with Apple's Time Machine backup software, and they'll arrive in capacities including 320GB and 500GB (My Passport) / 1TB (My Book). Both units should be available now for between $129.99 and $179.99.