Hey Cuuks -
First let me say how excited I am by this! I'm a software engineer (on Adobe After Effects) by day, and a hardcore cook by night, so this couldn't be more up my alley. When Karen and Andrew Dornenburg came through Seattle on their book tour, I pitched an idea similar to this to them - I wanted them to take the combinations in the Flavor Bible and put them online in a smart way like this.
And I'm impressed, the site is already very useable. As it happens, I came home with some kumquats today and only a vague idea of how I wanted to use them, and I used Cuuks to quickly brainstorm some combinations - one cold avocado soup amuse, and a chocolate dessert. The experience was really fluid and engaging. If you never did another thing to it, I'd already use it regularly.
All that said, here is my feedback so far:
(1) I noticed right away that both kumquat and kumquats are in the dictionary. Similarly with spring onions / green onions / scallions. Some amount of automatic mechanism can help with this sort of thing, but nothing is going to substitute for a human expert. A friend of mine owns and operates CellarTracker.com and he spends a huge amount of time on database quality control, making sure each wine is uniquely identified.
(2) Minor bug: you can add the same ingredient twice to one composition.
(3) It would be great to have quick links out from any ingredient to reference material on the web: wikipedia, tastespotting / foodgawker / et al, blogs, google, google image search, foodista and so on.
(4) As you have more people using it, quality control becomes an even bigger issue, as I assume you are weighting suggested combinations based on how frequently they occur in compositions already in the db. Even if the unwashed masses think pineapple and syrup of ipecac go together, I don't want any. So you might need some type of social voting or user similarity ranking, or some other way to decide whose combinations weight most heavily.
(4.5) Hmm, or I wonder if you could actually mine the web for combinations. That would be cool. Point a spider at websites with trusted recipes and let it determine from textual adjacency what goes together.
(5) Having the combination "meter strength" right justified looks awkward to me. It is just so standard to have the bars or stars or whatever run the other way.
(6) The label "Find Ingredients" to me only immediately suggested typing ingredient names. It took me awhile to realized I could type tags there too. Maybe rethink that label.
(7) It might be good to promote certain kinds of tags so that they were suggested when an ingredient was entered. I.e. to encourage each ingredient so that it was tagged at least with texture, possibly season, vegetarian or not, gluten-free or not, and so forth. That would also encourage those tags not to get a bunch of synonyms. Keep the free-form taggging too though, it is very useful.
(8) The idea I had pitched to the Dornenburgs was along the lines of a mind map as a way to visualize compatible ingredients. The problem with most mindmaps is they are hierarchical. You can pivot a node to the center, but you can't have an arbitrary web of relationships like you need for food. I don't have a precise idea of how it would look, but if you are interested in it, I'd be happy to brainstorm it with you. I'll never get around to doing it myself, I just want to use it!
(9) It would be nice to be able to re-order the ingredients in a composition and maybe attach notes to each of them. So I could see right in the composition what I intended to do with each component instead of only in the overall comp notes.
Phew! Too many ideas. You guys are pros so I'm sure you know people only give you feedback when what you are doing is exciting and worthwhile to them. I think this is awesome.