It depends on what portion of Lotus Notes you would like to sync.
I've got a "working" solution to sync email and calendar entries to my iPhone from a corporate Lotus Notes environment. I've gone through several iterations of this on http://technobloggle.blogspot.com/
I am currently using VistoMobile to "push" the email from my Lotus Notes account to the iphone. It does keep the inbox in sync with the iphone using an IMAP interface for email and a desktop component installed on a connected workstation.
VistoMobile also has a corporate directory lookup capability. On the 2nd iteration of trying this it seems fairly stable.
Calendar entries are another story. I am forward calendar events in Notes to another email address. I am currently using Live Mail with the httpmail plug-in under Leopard. This allows fairly easy updates to iCal and also allows me access from behind the corporate fire wall. Entries that I add on the iPhone, I forward to the corporate account and import them into Notes.
As I said, "working" but certainly not ideal. Currently running 1.1.2 on the iPhone.
Just got this to work for me (not perfect but at least it works):
Desktop Machine :
Windows XP Corporate Image
Lotus Notes 8
Outlook 2003 (2007 won't work with this solution)
Domino Connector for Outlook (free from Microsoft)
Itunes
My company uses Notes as the mail client, Domino as the server, does not run IMAP on the server and the whole system is behind the corporate firewall with no web access.
1. Contacts / Calendar Syncing via USB
> Install Outlook 2003 to your work machine
> Install Domino Connector for Outlook
> Ensure you can work your Mails, Calendar & Calendar in Outlook / see the folders etc
> Configure Itunes to sync your calendar and contacts to your iPhone
> Sync with Itunes whenever you want updates on your iPhone
2. Contacts / Calendar Syncing via Wireless
> Repeat the above steps
> Register in Itunes for a MobileMe account ($79 a year I believe)
> Once your work machine is powered up, syncing now works to the iPhone via Push
3. Email Syncing via Wireless
> Create a mail rule in Notes that forwards the headers of any mail with a body in excess of 1 byte to your MobileMe email address
> You could forward the whole mail but that tends to be a faux pas for corporate security
The contact / calendar syncing over wireless simply needs you to keep Notes, Outlook and MobileMe running so that your iPhone gets Push updates. The mail rule works from your mail file on the server so your work machine is not required.
This is by no means a perfect solution, quite the opposite in fact. The VPN client on the iPhone does not work with my corporate setup and I have not tried the new iNotes for iPhone yet but without the VPN portion it would not work for me anyway.
I sync my iphone with this application zennotes it includes a calendar application and contacts. I can synchronize my mail, my mail and have access to the corporate directory with lotus notes.
I give you the coordinates of the website:zennotes
