There are a few options here:
There are apps which can forcibly move applications to SD even when the developer has not permitted this. There are risks involved - some apps just won't work, and it might cause worse problems if you are unlucky, so I'd do a full backup (nandroid) before starting this. Titanium Backup can move apps this way, and if you haven't got that app already you should anyway
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Do note that you should not move an app whose widgets you use to SD, as the widgets will stop working.
Another approach is to move apps to a separate partition on the sd card. I don't know Wildfire S ROMs, but on my similarly limited device (Desire) many custom ROMs come with this built it. There's also an app called Link2SD which may let you do this on your current ROM. Normally an ext3 or ext4 format partition is needed for this (partitioning is likely to wipe the card, so back up first!). With this approach you can move the dalvik cache too, which saves more space than just moving the apk (but if you are using Gingerbread moving to SD the built-in way moves library files, so for some apps that saves more space). I'm sure people in this forum can make suggestions for good ROMs for this.
I'd also note that none of these methods move everything - app data remain in internal storage, as do some elements of the app, so apps still use some internal space. Titanium Backup Pro does now seem able to move application data to SD - I've done this with a couple of apps that were non-critical (i.e. no big problem if they broke) but using a lot of data, and it seemed to work, but I've only done this for these few apps (I reckon it could slow the phone down if nothing else).
I'm sure other people in this forum have faced this problem, so it's probably worth having a read round here - hopefully you'll also get some suggestions from the people who know this device
