I was all excited to discover Evernote for the Palm Pre last night and immediately downloaded it and installed it on my Pre. After spending a bit of time with it though, it needs some work to make it more functional for me. You can create text notes and have them synced to your account, but most of the other functionality is still under development and not that refined.
After launching the application and logging in, you need an Internet connection to use Evernote at this time, you will see all of your notes that you created. You can view your notes, but you cannot listen to any voice notes you may have since it doesn't appear that WAV files are supported on the Pre. There is also an issue with zooming and panning in on image notes you capture. A tap will zoom in, but only into one corner of the image and if you try to pan then it just zooms back out. There is also no landscape support at this time.
One last limitation is that photo notes are sent to your special Evernote email address and do not sync up through the application like text notes do. If you primarily use text notes with Evernote then you may be just perfectly happy with the current version. I use it to take photos of business cards and that has limited support at the moment.
One thing you will see on the main Evernote Pre display is a search option in the lower left corner. Tapping this will let you filter notes by Most Recent and Search nearby. The Search nearby uses the geotagged notes and finds them if you are near where they were created.
To search through your notes, you simply start typing away on the keyboard (a search box will appear) and see your notes automatically filter.
One other tip, when you create a text note, make sure to tap the envelope/folder icon in the bottom left that acts to save your note. I think a new icon is needed soon to clarify this issue.