PhotoShop will do it CS3 has "Save/Export for web" allowing you to cut it up... or not. CS2 may have the ability too... look in the help menu.
Cons of PhotoShop web page converted to html
There are still a surprising number of people out there on dial-up... an image heavy website (where the images are just the web page decoration rather than illustrating anything) is dire for bandwidth consumption. Who is the audiance for the website - big corporations with buckets of bandwidth or mum at home?
While search engines will use 'alt' attributes to understand that an image header has the words "Company Such-n-such Ltd" in it, I'm not sure how good any computer based conversion is at creating sensible alt attributes. Search bots are text based creatures, they don't look they only read words. Most conversions create code heavy pages which are more likely not to be W3 compliant in the end.
Creating an interface that is so image based doesn't allow for a truly beautiful fluid layout.. it ends up being yet another fixed width website... sad.
Pros.... er.... hummm.. it can look pretty. Yeah...
Sorry if that reads a bit harsh, not meant to criticise anyone - I'm perhaps over emphasing the statement "not the ideal way". I suppose it can feel like a friendly easy way to produce a web page that's a bit glam, if you feel comfy with PhotoShop., so hey, if it gets you started - go for it. Just be prepared to completely re-work it and do look at the code produced. Don't be scared to.