Synchronize Google Calendar on iPhone
Note: This should also work on the iPod Touch
iPhone OS 3.0 introduced support for CalDAV and ICS - that means it's really simple to sync with your Google Calendar:
Start by going into Settings:
Go into "Mail, Contacts, Calendars", then "Add account..."
Add a CalDAV account and fill the details:
If you check your calendar, it should sync
You can also add all your other calendars by adding a "Subscribed Calendar"
Start by going to the settings for the calendar you want to add:

Click on the "ICAL" link to get your Calendar's private address

It's usually a really long link, so start by putting it under your drafts or email it to yourself. Add another Calendar account (not a CalDAV this time, but a "subscribed Calendar" Then copy-and-paste into the Server input box specifying URL to the .ics file)
Google Wave adds online-status indicator

This was the biggest lacking feature in Google Wave (for me) for a while. Nice to see it added!
Gmail cleans up navigation
Big thanks to Gmail for taking out the annoying 'sites' from the menu:

Awesome.
Google Wave: View all public waves
Search for with:public and you'll have enough to keep you busy testing.

Update: To make your wave publicly viewable, add this "public@a.gwave.com"
Note: You have to add it in the contact list on the bottom-left of the screen. It might not accept the email address, but just press enter anyway and it should work.
Note2: Sometimes the address will disappear from your list - in which case, add it again (I know, it's annoying).
Google Wave
Got my invitation for Google Wave this morning and I'm already seeing just how useful this can be for collaboration. Especially from a developer's point-of-view: Imagine real-time code-reviews, or dare I say, extreme programming (XP) across continents?.
The editor isn't half-bad at all - it recognizes Tabs (unlike Gmail)

To make it better, pressing Enter at the end of the line goes to the start of the tab, as opposed to the start of the new-line (awesome!):

The other thing I've noticed is there isn't any mention of overall space-limitations.
More to come later...
Gmail adds undo-send-email in labs
How many times have you sent an email message and immediately wished you didn't?
Gmail has added a feature that people have been requesting for ages. If you enable the feature (in labs), it adds a 5 second delay to your emails being sent. During the delay, you have the option to undo the email being sent (Awesomeness).

I have to wonder how long it's going to be before other webmail services copy this feature.
Gmail introduces custom themes (awesome)
Gmail has added the ability to edit your own custom theme-colours. Click on settings -> themes -> "Choose your own colors" which then opens a window where you can edit colours. The changes can be saved and seen immediately.

Example:
