I mean if you put something in the calendar it will upload to the calendar linked to your gamil account so you can view it online.
Oh right, yeah. That bit is cool. Just never heard it referred to as a cloud before. 
The "cloud" is a very popular term nowadays. Refers to anything where your data is stored remotely yet easily accessed by you via a phone/PC - Google's new chrome operating system (for personal computers) operates almost entirely in the cloud. Things like Youtube, Spotify, Gmail, Calendar, Google Docs, FlickR are beginning to operate on these kinds of principles.
Anyway, my recommendations, in addition to some of the above.
Opera 5 - it's amazingly fast, only lacking pinch-zoom.
FeedR - probably the best RSS reader on Android. Simple and effective.
The Weather Channel - better than the default HTC Sense weather app, just a shame it's so ugly.
Movies - integrates with some movies facebook plug-in but it's great just using it on android - searches for nearby cinemas, you can look through listings for the next week or so, check reviews off rotten tomatoes, your facebook friends, etc. Also lets you open trailers, synopsis and so on.
Listen - Google have really improved their podcast downloader. Not perfect but very good if you're into all that.
3 - Vastly better music player than the default. Shows albums on a 3d box, easily lets you scroll through by moving round the box. Has a very effective album art finder, easily did almost all of my library in just a few minutes. Still in beta so looking forward to even more improvements. Very hard to find using the android market due to the stupid name, but here is a QR code to scan into barcode scanner.
