Picasa's Hello integration is pretty nice. You simply select photos from your album(s) and click on the SEND HELLO button, if you are within Hello already, you can select photos from your Picasa album or use Internet Explorer to find other photos on your computer. Hello is free, and you can use Hello without Picasa, but it does integrate well with Picasa.
There are options to have photos sent from your friends, to a different folder, so it won't appear in your own personal album. Photos can also be re-sized before they are sent your friends as well. Many other options are available as you can see below.
I particularly like the smilies on Hello. You can be very creative and surprise new users.
One of the features I found useful, was the web capture feature (currently only available for Internet Explorer). Simply click on the Hello camera icon in your Internet Explorer toolbar, and Hello takes a screen capture of the page and sends it automatically into Hello to be sent to your friends. Your friends simply click on the neon green "Web Link" button.
If you don't see a camera icon in your IE toolbar, you may have to add it to your toolbar, depending on the settings of your browser.
PROS
Fast photo-sharing client--worth its weight in gold
Friendly interface
Ability to re-size photos sent to friends
Original smilies add a unique style
Customizable for advanced users
Doesn't conflict with programs like other online chats (as far as I can tell)
CONS
Photos are automatically sent to your own Picasa album (this can be very tedious if you viewed a lot of photos from several different people and you want to delete the photos)
Suggestions
Option to close photo sharing side of Hello, and just view the chat area (reduces the overall size of the window and makes it much more convenient on your desktop)
Multiple users in one chatroom
Block selected users
Appear Offline to selected users
Photos being viewed, should have an option to be viewed only during the chat sessions (enabled by the sender), and not have them sent to another person's computer
Final Thoughts
Hello is something every photo enthusiast should try. It's simple, not too complicated, and can really make for an enjoying time when sharing photos with friends. There are things which should be added to Hello, and I am sure these added features/requests will make Hello an even better attraction to not only novice photographers, but professionals as well. If you want a fast, friendly, and just an overall fun experience in sharing your photos with friends, I recommend Hello.