I'm big into organization (GTD), and I've been a big proponent of iCal and MobileMe since its inception. But we're in 2011, and it's honestly frustrating that Apple is not seriously attempting to address these issues around MobileMe and iCal (Mac) and Calendar (iPhone), especially given the high annual price tag associated with MobileMe. I think I'm going to try and lay them out here, and then submit a ticket to the MobileMe and iCal Apple group (engineers) by linking to this thread. In my opinion, these issues are likely to be typical of those faced by 95% of users, and seriously needs tackling. If there are other issues as well, please feel free to list them on this thread, and I'll add them to the top of this list as well, if need be. I have a gmail address, work email address and mobileme email address. (a). A business collaborator sends me a calendar invite to my work email address. When I click on the invite on my macbook pro, the invite gets added to iCal with the option to 'accept', 'decline', or 'maybe'. So far so good.. ....I click accept: .........(a.1.). If in my Mail.app my personal gmail address was last used, the response goes back from my gmail address without providing me with the option to choose from my gmail/work/mobileme email address. This exposes my personal gmail address to business relationships. If users have 10 different email addresses, as you might imagine, this issue is a lot more complicated. This issue was reported many times in the past and even here in 2009, but Apple continues to ignore providing a simple fix (see solution below). .........(a.2.). Since this email was NOT sent to my MobileMe address, accepted iCal invites only stay "On my mac" and cannot be moved to MobileMe. This is problematic, because I now cannot see those invites on my iPhone/iPad, and my secretary cannot see it on her mac. This complicates itself for those that have large organizational calendars and opt to use MobileMe for the purpose. (b). My fiance sends me a calendar invite to my gmail address. Same issues as in (a.1.) and (a.2.) persist. The problem is further compounded by the realization that since she relies on her iPhone calendar and if my gmail invite is not synchronized to MobileMe (because of a.2.), she does not get confirmation if I can make the florist appointment. End result: I'm not getting anything tonight. (c). Accepting invites on the iPhone is grievous, because there is no reliability as to whether it even gets added to the calendar or whether the right email address was used in sending the response. (d). Calendars that are "On my mac" can no longer be synced to MobileMe, unless you export and reimport to the respective MobileMe calendars. It used to be possible that you could put whatever calendar wherever on iCal and it would sync to the iPhone/iPad, but Apple has taken a step back in that direction (akin Microsoft). Solutions: 1. Remove all email addresses and ONLY use MobileMe. Everything then works apparently perfectly in Apple's realm of MobileMe. Obviously this is what Apple wants and would like to force you to do. Unfortunately for Apple, some of us are not resolute loyalists, and would like to function efficiently in a business world and have a personal life as well. Using MobileMe for a business email address is not feasible for the majority of professionals. 2. There is a solution for (a.1.), where an AppleScript file is modified and placed directly into the iCal application bundle. I use this solution and it works for Snow Leopard (10.6.4). The problem is that every time Apple decides to update iCal, we need to repeat this mod. When something like this simple fix has been available (since 2008 as can be seen from that link), I don't know why Apple has turned a blind eye to this, which brings the point back to the fact that they think that majority will relent and move to MobileMe permanently. Subtle but crafty of Apple, I'd say.