Paul
You can set Photoshop (or any image editor) as an external editor in iPhoto. (Preferences -> General -> Edit Photo: Choose from the Drop Down Menu.) This way, when you double click a pic to edit in iPhoto it will open automatically in Photoshop or your Image Editor, and when you save it it's sent back to iPhoto automatically. This is the only way that edits made in another application will be displayed in iPhoto.
Otherwise
There are many, many ways to access your files in iPhoto:
For 10.5 users: You can use any Open / Attach / Browse dialogue. On the left there's a Media heading, your pics can be accessed there. Apple-Click for selecting multiple pics.
To upload to a site that does not have an iPhoto Export Plug-in the recommended way is to Select the Pic in the iPhoto Window and go File -> Export and export the pic to the desktop, then upload from there. After the upload you can trash the pic on the desktop. It's only a copy and your original is safe in iPhoto.
This is also true for emailing with Web-based services. If you're using Gmail you can use
THIS
If you use Apple's Mail, Entourage, AOL or Eudora you can email from within iPhoto. With 10.5 you can access the Library from the New Message Window in Mail:
If you use a Cocoa-based Browser such as Safari, you can drag the pics from the iPhoto Window to the Attach window in the browser.
Or, if you want to access the files with iPhoto not running, then create a Media Browser using Automator (takes about 10 seconds) or use
THIS
Other options include:
1. *Drag and Drop*: Drag a photo from the iPhoto Window to the desktop, there iPhoto will make a full-sized copy of the pic.
2. *File -> Export*: Select the files in the iPhoto Window and go File -> Export. The dialogue will give you various options, including altering the format, naming the files and changing the size. Again, producing a copy.
3. *Show File*: Right- (or Control-) Click on a pic and in the resulting dialogue choose 'Show File'. A Finder window will pop open with the file already selected.
Regards
TD