I love working in Illustrator, but ever once and a while, I need to export a file to Photoshop. Illustrator gives you the ability to export to Photoshop while preserving important information. You can export Layers, Color Profiles, Resolution Specification, and Text Preservation. This is great for exporting website wireframes or sprucing up illustrations.
Go File > Export and choose Photoshop (psd) for the Format option, to bring up the Photoshop Export Option dialog. Here you can change the Resolution, Color Profile, Layer Options, Text Edibility, and so on. One thing to note is that your Document Color Mode has to match the Color Model in the export options for the ability to Write Layers.