Make snow leopard more like lion:

you can use most of the features of osx lion / icloud right now.
using google.

mail:
to sync all your mail on all your devices you need gmail.
this first post will show you how to setup gmail in your macs mail.app

this post will show you how to get all of your existing email accounts forwarded into gmail and have the replies come from the correct email address

contacts:
this will show you how to get all your contacts from google contacts into your addressbook on your mac with two way sync

this will show you how to get all your contacts from google contacts into your iphone / ipad with two way sync

notes:
this will show you how to sync all your google notes with your iphone, ipad and ipod touch.

if you have your mail.app synced to your gmail account then the notes will appear there too :)

here is an alternative method, using simplenoteapp

now you have your mail, notes and contacts synced between all devices.

calendars:
this will show you how to sync your google calendars with your calendar on your mac.

this will show you how to sync your google calendars with your iphone

now you have all your calendars synced. anything you add on any device is available on all the others [and in google…]

this will show you show you how to get your basecamp calendars into google [and thus into all of your devices]

and this will show you how to setup basecamp to add todos and milestones by sending an email :)

by this point you have a lot of the features of lion :)
you have:
syncing of email between your mac and your iphones and ipad, and you can access it on the web.
syncing of calendars between your mac and your iphones and ipad, and you can access it on the web.
syncing of contacts between your mac and your iphones and ipad, and you can access it on the web.
syncing of notes between your mac and your iphones and ipad, and you can access it on the web.
syncing of todo lists [via basecamp] between your mac and your iphones and ipad, and you can access it on the web.

add in dropbox / google docs and you can have syncing of documents too.