I mostly use the IC strips ($20 for 100) because I usually go through about 10 per cycle. When I get what I think is a +opk with the strips, I then use a digi to confirm. I never get a true +opk (ie test line darker than control) with the strips, but I get a line that is close.

I currently get the IC ones through ebay (inpregnancy store), but I have also used the Oracle ones.

Definitely don't use FMU if you've never gotten a +opk with it! The conventional advice is to not use FMU, but there seems to be something of a growing trend to use FMU for some reason. I always get a lighter line with FMU than the night before or later that day. For example, this cycle, I had 2 very dark (but not +) opks on CD15, FMU CD16 was much lighter, then 10pm on CD16 I got the +opk.

I think the theory behind not using FMU is that you don't metabolise the LH from your bloodstream into your urine while you sleep? My advice is to skip FMU and try to do the test after a 4-hour hold with minimal liquid intake during that 4 hours. I usually try to pee 2 hours before I leave work so that I can do the test when I get home and settled (ie after I change clothes, put things away, etc). Or I do the test right before bed. I've had many a +opk at midnight...

I can think of 2 reasons to use OPK if you're charting temps:
1. To confirm what the temps are telling you - this is great if it works but frustrating if they don't match up (like mine!). I tend to actually put more credence on the OPKs than the temps now.
2. To have warning before you O - temps only tell you after you have O'd, so it's too late to BD by the time the temps have confirmed O. The idea of the OPK is to make sure you know beforehand to BD at the right time. Of course, if you have a very active sex life, the OPK is probably not really necessary for that purpose.

Taurean, thanks for the tip for finding the digis cheaper on ebay! Best price I've found in Australia is $53 for 7 and I struggle to justify that expense (about $7.50 per test) but I like the confidence I get from the results. If I can find them cheaper I'll definitely buy more! (I've made this first box last me almost a year!)